I didn't want to double post, but so be it. Thank you everyone for your efforts. I have compiled my notes and the write-up is here.
The write-up will be split into pros and cons, long range, mid range, footsies, close range, edge guarding, general summary and overview. Again I will not give a match-up ratio. That is NOT what this is about. With that said, here it is.
Marth
Pros +
+ Falchion gives his attacks a disjointed hitbox
+ Strong footsies due to good pokes and solid mobility
+ Great edgeguarding
+ Strong OoS game/punish game
+ Good at trapping and getting out of traps
+ Great killing potential due to tippers
Cons -
- Lightweight. He gets knocked around easy and can die early
- Commits hard to many of his best attacks such as Dancing Blade
- Can be too reliant on traps to secure kills/ No kill confirms
Bowser
Pros +
+ Heavyweight. Will not be KOed easy unless tippered
+ Huge damage. Trades are in his favor and makes his pokes dangerous
+ Solid footsies due to range of his pokes
+ Command grab great for mix-ups
+ Extremely high knockback on kill moves means he is always in the fight
+ Up B OoS is the best defensive option in the game
+ In a constant state of light armor. Will not flinch from weak moves.
Cons -
- Huge body makes him vulnerable to air traps and is a weakness in footsies
- Has no real safe buttons on block besides retreating bair. Commits heavily to basically everything he does
- No kill confirms. Needs a trap situation or a hard read
Long Range
lolwut? Nothing to say except one or the other will try to close the gap since they can't do anything at this range.
Mid Range
Bowser's neutral b fire breathe will see work at this range. Won't cause flinch near max range, but is a good way to deter ground approaches and tack on an easy 13% or so. This is really the first hurdle Marth must get past. Of course he could opt to just eat it and then work his way in since after using it Bowser has to let the move "cool down" since it withers the longer the fire breathe is active. An easy way to draw this out os dash to shield and then shield drop dash in or SH when it dies out. Full jumping works too. Other then that, alot of baiting can go on at this range. Both characters are strong in footsies, but tend to commit though Bowser more so than Marth. Ideally both characters want to slow down the pace of the game and force their opponent to get through a wall they set-up. However since both chars have the same general gameplan, it comes down to who plays it better.
Footsie Range
Both have strong reliable tools to win the footsie war. All of Bowsers attacks are powerful and devastating. Two hits from d-tilt can do 25%!!!! Other attacks do around 12% to 14%. He has nice reach and power to back up his attacks. Marth has his sword giving him a disjointed hitbox to work with. He doesn't hit as hard, but he is more fluid and can maintain advantage better once he gets a hit. Attacking in wide sweeping arcs lets him cover several angles of approach and keep Bowser at bay. Marth is also a slightly better punisher and since Bowser is less safe on block this opens up opportunities for Marth to score damage. Bowsers tilts are not safe so attacking a shield is not a wise decision for him. The best time for him to hit a button is when he thinks Marth is going to press something or to snuff an approach, otherwise expect to be blocked and punished. And since both characters thrive at the same range, this puts Bowser in danger of getting tippered and killed at percents that are normally unheard of for a character as heavy as him. He can be KOed as early as 80 or 90% depending on Marth's rage and their position on the stage. Of course Bowsers killing power is very impressive as well and cannot be discounted. Bowseer also has a better dash attack for disrupting Marths wall and breaking his rhythm. Marth has two interesting tools at this range. Dancing Blade and Shieldbreaker. Both are transcendent. They will not interact with hitboxes only hurtboxes and shields.(Items too but competitive play is no items.) Excellent footsie tools. DB is a great whiff punisher while Shieldbreaker is a good poke due to long horizontal range and can decimate shields. Marth also has great walk speed and air speed so he is more in control of the pace. this helps mitigate Bowsers large damage advantage since Marth can more easily dictate the matches flow. Still as great as his specials are Shieldbreaker is very slow to start-up at 20 frames. Well within human reaction time. You can roll or spot dodge on pure reaction as long as you are paying attention. Marth needs to throw it out when he feels Bowser will shield or press a button. DB is bad on block as well and easily punishable though Marth can mix-up his swings or stop short so a punish is not guaranteed. Counter poking is all about knowing what buttons each character likes to press. SH fair will from Marth beats Bowser's fair but an f-tilt from Bowser will often beat Marths fair. SH neutral B from Bowser is strong vs Marth's d-tilt but will lose to dash back Dancing Blade. Knowing spacing and positioning is key as well as reading habits and knowing what options beat what. Bowsers Fire Breathe will get use here as it blows up Marth's spacing and does good damage. Both characters also have good u-tilts to shut down obvious SH attempts. Marth's jab is strong for this as well. Though it must be spaced well because it is unsafe on hit.
Close Range/Mix-ups
Neither character is very strong up close when it comes to normal pressure. Both are very punishable by the others Up B OoS. They have great defensive options so generally whoever becomes TOO aggressive and sloppy will get punished. Both their Up Bs do a nice 11%. Bowser's is better since it puts his opponent into an air trap scenario, with Bowser still grounded. Bowser however is scarier vs a shield since he can mix-up with Koopa Klaw, his command grab. This does 18% and has regular land recovery of 3 frames when done in the air. It can kill at higher percents as well. Scary stuff. At higher percents its harder to influence the direction of the body slam. Marth generally wants to get back to footsies where he excels and safe shield pokes with d-tilt. SH backwards Fair or Bair is a solid tool for resetting spacing. Bowser can do the same with bair. Both characters can use grabs to reset spacing as well. Marth's throws can easily send Bowser flying towards the ledge where Marth excels. Bowser can do the same, but its a bit harder for him to stay in control due to his mobility. BUT his reward for landing a hit is huge, so trap situations can lead to huge pay offs. He also has another high risk/high reward option up close with his down B. The headbutt launches his opponent then he slams his body down. Lots of damage.
Edge guarding/Ledge traps/Air traps
Edge guarding is Marths realm. Its easy for him to simply run out and swing and beat out alot of Bowser's options. He can do the same on defense too or even counter. Speaking of counter, Bowser's Up B when used for recovery is counter bait. Marth can rack up alot of percent here even if he doesnt get the kill. Bowser has some strong options too. Run off bair to catch rising Dolphin Slash can be deadly although its techable so its not a guaranteed kill. Both have straight forward recoveries so edgeguarding is effective vs both these chars, though Marth gets a slight nod here. For ledge traps both chars are strong at them and thrive on them. Neither are combo machines so putting opponents in situations where they are limited is what they are about. Marth is a bit better at dealing with these due to having a smaller frame, as well as ledge jump fair being a solid option. Generally though whoever initiates the trap has a nice advantage over the defender. Bowser is very threatening with that Koopa Klaw as a regular get-up into shield could mean a free 18% for him!! Air traps are what Marth is known for. His throws have high knockback and send opponents reeling. Bowser however is not helpless. Bowser's down b though risky can yield huge reward if it hits and kills well too. It can make your opponent hesitate when attempting an air trap. His Dair is another similar option. Marth can counter these if he baits them however. On the flipside Marth is pretty good at dealing with air traps. B-reverse Shieldbreaker is nice for messing with an opponents momentum as it will send Marth in the other direction. He can also choose to challenge with dair which can work due to its range and disjoint, though this has alot of recovery so if its baited Marth is in trouble. His counter can also be used in these situations as well. Bowser is not as strong in air trap situations, but once again his high damage and extreme knockback can seal a stock with one correct guess or mix-up. A uair from him in a juggle situation does 15% and can kill a little over 100% or less depending on rage and Marths air height.
Overview
They are honestly slightly altered versions of the same archetype. Both are strong defensive footsie types, while Bowser leans more towards being a grappler and Marth a poking character. Bowser has insane power and mix-ups, while Marth is safer and a bit more nimble. Neither are combo heavy characters. They rely on solid fundamentals, good decision making, proper spacing, as well as solid reads. They are imo true fighting game characters. Nothing is free with either one. This match is darn close and a great one between two that have mastered their characters. They each have weaknesses the other can exploit. Both have the tools to win and neither one dominates the other. Whoever is the stronger player will win.
Guys thats the write-up. How did I do? If you feel I missed anything then please let me know.
