Ah, Sonic discussion, now you're speakin' my language!
SA2B was a very underrated port of an awesome Dreamcast game. I loved the skater-punk style (at least when it first came out) and the fluid controls cannot be denied. I loved the little touches like being able to misty-flip if you jump mid-roll. However, its not without its problems. The levels are extremely linear, especially when compared to SA1, and while I never noticed it as a kid, the camera is insanely wonky. It's a pain when it locks back to where it was before when you decide to move. I loved the plot as a kid, even though I liked SA1's more, even then, but today I can see that's where it started to go downhill.
Still, it was the last time Shadow was undeniably awesome. And British sounding ;P
Basically, SA2B was the last good Sonic game on consoles (not counting the Advance series which is pretty good, as is the Rush series) until Sonic Colors came out a few months ago. Colors wasn't perfect, but if they inject a little tiny bit of the Adventure/ Adventure 2 magic into it, the formula they use could be the winning one :)
aaaaand end fanboy-geek-rambling :)
P.S. also, did anyone master the massive shortcut in the Final Rush stage :)?
As for the Chao, my brother and I spent a ton of hours on those things. This was a place SA2B was vastly superior to its original, considering they added the stats window. I sunk more hours into the original, however the superiority of SA2B's system is undeniable :)
I loved being able to see the progress of going between light and dark chao, and the Chao Black Market was a nice touch. I never could actually master the racing/ karate portions, but I enjoyed just raising the little guys more than anything. I miss chao, and once Sonic Team can make an undeniabley awesome Sonic game again, I'd love to see them return (But only after they can master the core gameplay ;) )