At lower levels of play, Snake is considered "cheap." At higher levels of play, Snake isn't nearly as effective as Metaknight.
Actually this isn't true at all...MK just seems easier to use for n00bs.
Snake is cheap but only if you use his cheap moves in cheap ways. For example, my friends at college usually use b-moves, dash-attacks, and smashes. With Snake they're dumbfounded that this is a "cheap" char, b/c none of his moves seem to be very good (he's very slow). Snake is extremely weak in the air, and many of my n00b friends don't know the proper way to get back down to the ground (they always try landing right above me and attacking). For my other friend who actually has mindgames, Snake was the easiest char to use. His approach takes almost no effort:
(1) Walk slowly toward opponent
(2) Do first hit of ftilt
(3A) If shielded- stop and go back to (2)
(3B) If not shielded- HIT OPPONENT with second hit and pwn
That's pretty much all he had to do. It took him 3 minutes to get Snake's dash cancel down, which is obnoxious, and he learned Snake's other cheap moves and their proper usage:
Utilt: Use to KO, hits in front and above ridiculously
Side-B: Gets enemies off the ledge/ledgeguarding
Down-B: Stick to opponents, activate after utilt for VERY low % KO
Nair: Use immediately after leaving ground to get fourth kick out before landing
Down throw: Allows you to tech chase, easy to do with Dair or Fsmash
Yeah he's just ridiculous because he has the best tricks, best moves, and you can use his Down-B to get your Up-B back, making his recovery better than previously thought. I picked up Snake SOLELY because I knew he was cheap, and the chars I use (Fox, Peach, & Lucario) lack the same potential to win on a tournament level.