Sonic 2 is awesome indeed! The original Sonic is a classic with great level design and has the best special stage. Without the original there would be no Sonic games.
I've got one, and I must say, you sometimes have to finagle with it to get it working. But it is old CD technology, and it does have a few select games that make it somewhat worth the purchase, if you are not of the collecting type. And some games unique to the system, like the aforementioned SNATCHER (considered by many to be the definitive edition).
Of course, but this goes back to my original comment. You would buy it for your collection's sake. Nothing bad about that, but if you are not exactly who collects vintage games/systems, but want to play, why buy a Sega CD for only that reason?
Yeah. But if you're a collector, it must be awesome. For example, I already played every single Resident Evil game on an emulator, and RE3 on a real PSX, but I bought RE: Director's Cut just for the sake of having it. lol