I feel pretty confident in this match-up. It is true that Falco dies at very low % against Snake's ******** Utilt; however, with a good perfect shield game combined with jab mixups, you can even ground approach him while you're at high enough % to die. Snake's forward tilt will destroy this tactic over time, but it can be used sparingly, just as most effective approaches can. The bottom line is that Falco has almost every situation on his side as far as racking damage goes. Snake has only two options for damaging Falco: tech-chasing dthrows, and tilting/punishing with tilts. Neither one of these involve approaching, so while Falco outcamps Snake, he really holds the advantage overall.
Snake can easily rack up enough damage to kill falco in just a few moves, but with proper DI, the Snake will have to earn every one of those moves individually. Like stated before, Snake can only get one tilt off and it will send Falco into neutral position again. Falco has the ability to send Snake into a bad position with every attack, and can rack up damage in many more situations than Snake can. Killing him is tough though.
Rely on bair, and OoS dairs and bairs to put him in killing position. I personally love OoS Nairing to rack up damage at mid %. This gets a few good hits, and sends Snake nearly straight forward for laser followups, and can get him off stage. The biggest issue with killing Snake is that your Bair WILL be stale by the time you can use it to kill him. Try your best to mix up the moves you hit Snake with; using Uair and Nair help alot with this. Lasering and a well-timed reflector at high % can both help freshen your Bair and smashes too. (actually, maybe a long shot, but does anyone know if reflecting a grenade counts as using the move, if you're just trying to 8-move-refresh your Bair? You probably have to hit Snake, or a stage object (I love castle siege for this)) If you can hit Snake with an OoS Nair and Dair, an Ftilt, a jab, laser, reflector, Phantasm, and a throw (multiple throws can replace Ftilt which is hard to use against Snake) at high %, you will be completely Fresh on every kill move. This seems like a lot of work, but they are all easy to hit, especially since you won't be busy trying anything else at mid-high %. Keep a checklist in mind while racking damage, and you'll be all set to kill with a well-placed Fsmash, Bair, or Usmash. This tactic frees you up to actually use those three moves at lower %. Fsmash is particularly amazing for surprising out of a chaingrab. Dash attack-usmash is great too. Don't be afrain to use them at low % as long as you know how to freshen them up.
When you are around 90+%, watch out for Utilts (duh). At this time, Snake will almost always wait around in standing position, rather than crouching, which is great for lasers. Remind him that you can laser the heck out of his while he's standing, and he'll start crouching again. This makes it a bit tougher for him to pull his Utilt out instantly as you can then try to approach him.
Grenades can be very annoying. Especially for Chaingrabbing. Here's a trick to never blow yourself up if Snake pulls a nade during your chaingrab. Snake has to time a grenade pull very quickly in order to get it out before your next grab. This means he will not be focusing on trying to wiggle out of the grab itself. Take your time. Don't buffer the throw while grabbing. Listen for a pin sound inbetween grabs, and pause for a second after the grab. If he pulled a nade, switch to Back or Up throw. This is untested, but I'm pretty sure the throw itself doesnt set off the grenade. The lasers have a good chance of exploding the grenade at a safe distance and giving Snake just a bit more damage. Sure, this kills the opportunity to Chain-spike him, but if he pulled a grenade, you couldn't have done that anyway. Also, if you're brave, and good at timing, you can try holding him a bit longer before back throwing him, to cook the grenade a bit longer. This is risky though. Keep in mind that both Back throw and Up throw put Snake in a bad position (the air, and possibly offstage).
I definitely agree with 50-50 matchup here. Just lay smart, and Grab as often as you can.