I think much of the time, if you win game 1, you can win the set against Ike. Depending on the character, of course.
MK is worst. Marth isn't too far behind, IMO. DDD is bad. Olimar is.. meh, annoying. Snake would be in Ike's favor if not for his Ftilt, IMO. Diddy is quite doable, pretty even actually with conscious thinking and work (I did once take a game off Gnes in tourney). G&W is not bad, pretty even also with active thinking and keeping bad habits out of your game. Most other matches are probably 4-6 except our auto-wins like Ganon, CF, Bowser (yeah, I said it) and other decent matches like Luigi, Earthbound boys.
Sometimes I think Ike should be mid tier, but sometimes I can't think of a place other than very top of low tier for him. The reason for that is MK and the abundance of people who use him.
Also, Ike never has any options if you are in front and below him. It's true on the ground, too. Kirby and Snake and others can duck under jabs and grabs.