B2W2 has more to do in terms of end game, and it has a seemingly longer plot/story mode than the original BW. XY brings a pretty neat new story line alongside new pokemon and game mechanics. I played the hell out of W2, but I've REALLY REALLY played X. I have to say I enjoyed sixth gen more. However this might be because I enjoy the competitive side of the game. Wifi network for original NDS is down as of May, so you can't really do anything other than play story mode or RNG(if you know how to). If this is to help you decided which to get, I say go XY. Just play a rom of B2W2 on your computer if you really want to play it.