I completely agree with you, many of the mid and even low tier characters can and have been competing with the higher tiers in the right hands more frequently then the past games. One of the things I really like about Smash 4 is that the best character in the game, which is Shiek IMO, isn't some ludicrously good soul crushing force that 64 Pikachu, Melee Fox, and Brawl Meta Knight were. Oh sure Shiek is still really good, but she is an actual character with legitimate strengths and weaknesses, unlike the other characters (Fox less so but still not exempt) who are simply defined as "the best". Let's be honest though, the only reason this time around is any different is the fact that Nintendo could patch the game. Otherwise we would've been in for one heck of a ride with pre-patch Diddy and Rosalina.