I know this might sound like a typical droid fanboy reply, but here it goes...
I owned both an iphone 3g and 3gs. I switched to the droid back in december, and it amazes me how much better the droid is than the iphone. EVERYTHING on it is better than the iphone.
If you are having call quality issues, there is something wrong with your phone. Honestly. The call quality (and speaker volume) on the droid absolutely destroy the iphone i every way possible. Your phone is broken if it doesn't.
As for the laggy UI and web browsing, yes, that is somewhat true. Until you overclock. Remember, this phone is pushing 854x480 pixels compared to iphones 480x320. HUGE difference. Obviously less pixels = smoother scrolling. Also, this is a multitasking phone and uses widgets. Of course it's not going to be as smooth as a phone that only has one program open at a time and doesn't have widgets. Here, do this: download "backgrounder" from cydia (iphone), open up at least 3 different programs, and then let me know how smooth the iphone moves through everything. It doesn't.
As for the battery...once again, there is something wrong with your phone. ANY phone has a better battery than iphone. That's a FACT. If your droid battery is worse than the iphones, then there is something wrong.
Take your phone back and exchange it for another droid (just tell them your call quality is bad), root and overclock your new droid, and thank me later.