The 3DS Modern Sonic gameplay does look quite better than I expected. Although, that might be cause I was expecting it to be more like sonic Rush than the 2D segments of Unleashed day stages. But holy damn, that music is awesome.
Unfortunately, I doubt I'll be getting this. The PS3 and Xbox versions, gameplay-wise, are far superior to me, and the 3DS Modern Sonic, sadly, just doesn't quite cut it for me. However, if I had reason other than this to start playing my old, unused PS3 or Xbox, I would DEFINITELY get it. Especially after seeing the City Escape stage. The Modern Sonic, while still being recognizable as Unleashed Day/Colours gameplay, showed touches of SA2 gameplay, which, seeing as how SA2 is my favourite Sonic game, made me VERY happy, then very disappointed as I remembered I wouldn't be able to get that version.

. But, then again, who knows, I might get the 3DS version anyway. Depends how good it's reviews are.
Also, TS, I didn't even play the Classic Sonics a lot and I noticed that Classic Sonic Green Hill Zone was just a Sonic 1 Green Hill Zone Act 1 port.