To be honest I don't get how people prefer The Sims 2 over The Sims 3. I mean TS2 is fun and all, but seriously I can't go back to it no matter how much try. I guess it's just because I've got so used to the open neighborhood and the Create-A-Style tool that I can't play TS2 anymore.
And if you've got all the packs for TS3 there's nearly as much content as there was for TS2, the only drawback is that some of the stuff from older Sims is being sold in The Sims 3 Store instead of being in expansion packs.