I really, really want to say yes to bigger lots because, well, more is more! And I love to build. But honestly, I think the large buildings I've created on 64x64 lots don't perform that well in TS4.
Big houses take too much time for sims to walk around, and the sims end up hardly seeing each other. For business and community lots, the visitor numbers never really fill them properly and there's also problems with sims spending lots of time just walking around them.
My favourite lots I've made and play most have ended up being medium or small lots that I've managed to design well and include lots of stuff.
My major concern is not enough lots in each world. Still love 64x64 lots for some specific builds. At least one in each world would be good.
