What's laggy exactly? Have you tried a home/launcher replacement? It runs in place of the stock one and they're the only way to go as far as I'm concerned. I use Go Launcher EX, free from the market.
And on the iPhone note, go for it if you want but I could never. iTunes is ridiculous. And the thought of the iPhone browser preventing me from long-pressing a link in the browser to download a file is sickening. Small screen, can't replace battery, proprietary (expensive) hardware, bad at drop testing (from waist high), dropping calls...the list of negatives is crazy long. I wouldn't go from Android to iPhone, even a jailbroken one.
I too was thinking about going to the new iPhone after my D1 contract was up.. because yes, even while rooted and using a different launcher(which did help a lot), it was laggy. And me being picky I hate stuff like that. Even though I can do more than a jailbroken iPhone on a stock DROID, that lag was annoying me. It wasn't even a horrible lag always, but still. Sometimes I'd show friends with iPhone's something on my DROID and the app or going back to the home screen would take forever to load. It was embarrassing.
Then, I got the Droid 3.. and OH BOY does run HELL of a lot better. I can't believe I EVER thought of getting an iPhone. Lmao, ah man.. I'd be missing out on so much.
Agree with everything you said NoBloatWare. Just too many things you can't do with an iPhone and too many things I can complain about with Apple's phones.