WARNING: large wall o' text only for Brawl+ dewds
While I wait for videos to compile I'll write stuff about Brawl+:
In terms of physics, the game felt pretty good. Lots of stuff feels really broken, and in high-level play that turns a lot into just spacing to avoid said broken attacks (like Wario's dair) but in that essence I suppose it's not a whole lot different from Melee. Even in the small amount of entrants (5 teams, 9 players in singles, most people who wanted to play Brawl+ didn't come) there were a number of different successful characters. Ganon, Yoshi, Pit, Lucario, ZSS, Marth, Wario, Jigglypuff, Peach, and Metaknight were all represented.
Doubles was first, and I teamed with Vilt (maining Ganon). We were going to go double Ganon but I got cold feet and was scared about getting combo'd as Ganon, so I went Jiggs instead (also as I had just placed 3rd in Melee with her). From probably 7 tournament sets with Jiggs in Brawl+ I have some impressions. Her most useful tools are her uair combos, drill to grab (or just grab), and fair. If you land a uair in the air, at a huge range of percentages it almost always leads into 2 or 3 more uairs. At low percents on the ground, combining utilts with uairs can start a nasty aerial combo. Her grab is still really good, her pummel and throw damage are great (a grab is about 20%) and her dthrow can combo sometimes. Her drill with the autocanceling leads very nicely into grab, although honestly I didn't make use of this nearly as much as I should have (and do in vanilla). Her ledge camping is still good, drill is great.
My biggest impression of Jiggs is the huge power of her fair. It seemed to literally have much more knockback than even her fsmash. Fair just had huge power and I killed with it almost exclusively. I also got a few combos of 3-4 fairs off the stage for a kill, it chains well into itself.
After being knocked into losers' pretty harshly by Zero (with Lucario and Pit) and decided to screw it all and see if I could come back and win with Metaknight. Now, up until then I had played him a couple of times but never really wanted to test how broken he was - I always assumed he wasn't too good, just that his up b was still amazing, but who would ever go 100% in a friendly with MK just to see his boundaries? In my first set with him I 3-stocked and then 1-stocked Vilt, so I didn't feel too overpowered.
Then I had losers' finals with Karn (who used Yoshi). It took him most of the first match to realize that he had a grab release infinite on me, and the crowd went wild when he got a spike kill from it. He also used it in his counterpick on Castle Siege (which oddly wasn't frozen, even though it should have been) and used it for two kills on the walk-off transformation. The set was pretty hardcore, I won 2-1 or 3-1 (can't remember if we did best of 5 for the winners'/losers' finals or not).
Then I had about an hour of playing grand finals with Zero's Lucario... first set went to 5 matches, about 6 minutes each, and the second set finished in 4 matches. Every win was a 1-stock (until the last match). Through this set I really learned how to play Metaknight perfectly at grand-finals level, so here are the strats I used:
-Dash attack into up-b: dash attack was one of the few things I could do that Zero wouldn't punish perfectly. I could spam it a lot back and forth until it landed, and then pop an up-b. It's a guaranteed combo. Unfortunately, with good DI up-b still doesn't kill very early (took me probably 150% to kill with it) so this combo wasn't too broken, it was just very useful and safe.
-Dtilt and ftilt: Surprisingly, this was still really effective. With the less shield-based game, they are more of a surprise. And with the damage of the ftilt, it's quite a good tool. Dtilt-ftilt combo either gives solid damage from a safe range (out of grab range) or supplies strong shield pressure.
-Dthrow: Against a few characters I played, this was a chain-throw; against others, it can be a tech-chase. With a floaty character like Lucario, however (and Zero's upwards DI to escape a possible chain-throw) I could guaranteed combo it into a full-jump fair, which lead to other combos. Unfortunately, landing grabs was extremely hard and I maybe got 10-15 in the 9 matches of the finals.
-Dsmash: I actually spammed this a lot, especially after spotdodging an attack. It hit not too often, but when it did it counted and if it didn't it had low enough lag that Zero couldn't do anything in time from his shielding position (thanks to shield stun). Dsmash wasn't insanely broken, but it is a very, very nice tool and is especially good out of a dash (I used dsmash out of dash a number of times when I needed to punish a fall or lag that was far away from me).
-Fair: This was probably the best thing I started to use. Fair combos almost always into itself 2-3 times, and then into up-b. Therefore I could get dthrow-fair-fair-fair-up b for 30-40%, and early lead-ins for kills on close wall stages.
-Tornado: Well, it got better. The hitstun means that if you get caught, you're in for guaranteed 10-15%, which is great for the priority and safety. I always felt like I could have used this more and been more gay, but for what it's worth I did use it extra whenever I remembered, which was often. The reason I don't label this as insanely broken is because Zero, being a very very good player and a very aware player, was able to punish any random uses. Any time I used it without planning to punish lag or as a surprise, he either shielded the whole thing and punished, or used an fsmash/aurasphere/dair to hit me out of it. I was punished tons of times for using it.
My game pretty much consisted of going for grabs when I could, comboing fair and up-b, and spamming dash attack. That makes it sound a bit simple, and against Zero's Lucario it took a lot of focus and effort, but that's just what my play consisted of.
One last note about MK, stage picks: After my first set playing with him I realized that up-b would be a great tool for early kills on stages with close walls. This made Warioware my #1 counterpick, where it was easy to combo fairs into up-b for a 60% kill, and Green Greens my #2 counterpick, which obviously has very close sides as well.