Well, anyway, I've beaten the game 100% on the wii, and I honestly think it was worth the wait. It kicks the iphone version's ass. I LOVE all the secret paths (many people probably don't know about some of the really secret ones), there are secret paths in walls, or sometimes they'll encourage you to take a leap of faith for find a hidden path. There are even areas that ONLY super sonic can get to.
Having a cutscene before E.G.G station zone was REALLY cool. It shocked me too. It felt really classic there, it felt like something that would really be in the classic games.
The physics, although not like the originals, are almost as good to me. The air momentum IS an issue though. Still, you move faster on steep slopes when going up them and faster when moving down them, spindashing is as fast as ever, and if you don't have momentum, you can't get up a hill. Not to mention the fixed acceleration is nice. You can walk in place on walls, but only if you hold in that direction and then let go. If you're not touching anything, or if you fall from a high enough height, you'll slide down the slope like always.
I'd say the game is too short, but it's only episode one, so I guess it gets a pass.
Something I noticed is the strength of springs, bumpers in casino street, and the rebound have a certain oomph that they haven't had since sonic 3 and knuckles. Sometimes in post S3&K 2D games the rebound felt a little weak, the boosters didn't seem to speed you up a lot, and the springs didn't seem to really push you up. In sonic 4 though, all of that just feels RIGHT.
As for the overall quality, as I saw someone else say, it's better than sonic 1, it's as good as sonic 2 (I don't completely agree, but close), and it's not as good as sonic 3 and knuckles.
There's so much more I could say but I don't have time now, I'd give sonic 4 episode 1 a 8.5/10, and I can't wait for episode 2.