I've just about the same experience as you. The antenna issue doesn't bother me at all (and, overall, my calls perform better than they did on my 3GS), but the damn proximity sensor issue drives me up the wall on longer conversations. Hopefully 4.1 or 4.0.3 comes out with a fix soon.
Loved this review, there seems to be a lot of love/hate (mostly hate) for the iPhone 4 here. Had the device for a little over a month now and hadn't had one problem with dropped calls and I tried to grip it all sorts of ways and I'm in Texas which can be spoty lol. The sensor while talking is quite literally my own gripe about the device so I can't wait for 4.1 update to come out. I started using the headphone for longer conversations which i prefer anyways because I usually work while I chat.
Anyway, great review! I'm glad this got posted on the front page.