Some of Ike is really good, some of Ike is really bad. His range and power do not add up lol. But he's bad at dealing with pressure and getting back down to the ground safely. He's not OP, in that you can find MU's vs him that he definitely loses.
It's hard to tell for sure though, because I haven't seen a lot of strong players in P:M abuse his weaknesses, and on the other side I haven't seen top Brawl Ikes or people who are extremely experienced with the character fool around and show some stuff. For all we know, San or Mr. Doom or xyz Ike main could show us some really broken stuff or play him more efficiently (Fair on shield, we find out gives Ike a nice frame advantage, so they frame trap you with grab or something), and for all we know there will come a day where some Fox main makes the MU look unwinnable for Ike because Shine is so damn gay or because he has no answer to Nair or because Shine is so gay (definitely gonna be Shine).
What seems obvious though is that Ike is better than he was in Brawl, but he has different threats to worry about and it will be interesting to see if he can cover them or if he's just not fast enough or safe enough to handle the approaching and juggling pressure that's sure to build as people get used to P:M.