i bought a droid 3 on Wednesday and my wife went out and bought an iPhone4 on Friday...
My thoughts..
-iPhone has a better camera (I don't care how many megapixels are on android phones)
-Safari is a little bit faster than the android browser, but not by much
-Home screens go to droid, it's just way better and no widgets on the iPhone, advantage droid
-Smoothness factor goes to iPhone, I have experience much lag on the iPhone, i get it from time to time on my droid 3, but nothing like the Storm 2 I upgraded from...
-Display goes to the iPhone (its just a better technology), however, i love the droid 3 display, nothing wrong with it imho (I know people love to hate on it)
-Typing on virtual keyboard goes to iPhone, but the keyboard on the droid 3 is awesome and I prefer that over the iphone
-Screen size goes to Android. 4' is just right, i hate the 3.5' display on the iPhone, it is just too small, but that's just me lol...I would probably prefer the 4.3 over the 3.5 if your talking bionic vs. iphone
-Apps, not big on apps at all, but i really like the marketplace, but I do know iPhone has more apps to offer so I would say advantage iPhone in this category
-Notifications - SMS goes to iPhone because it's a pop up you can't miss, everything else goes to Android, I like the notification bar on the top of the screen. iPhone you would get a red bubble with a # in it if something new comes through. IMHO blackberry is the king of notifications, and that is the one thing I wish i could have kept from my Storm 2...
-Battery life goes to the iphone
-You can't root the droid 3, not sure if you can the bionic yet either. You can jailbreak the iPhone though...
So even though I felt that iPhone beat out android on a couple of things, they aren't any real deal breakers. I prefer the Droid. It's just a cooler device, i love the feel of it, the home screens and screen sizes were the dealbreakers for me. In terms of the bionic, the biggest dealbreaker would be the LTE (if you live an LTE area)...The droid thought is definitely an upgrade over my Storm 2, even though I feel blackberry has the best notifications in the phone game.