Here are my impressions after having used the Verizon iPhone4 for a full 7 days.
As background, I switched from a Droid Incredible (had it since Launch Day, 4/2010) and am a big fan of the Android OS. I jailbroke my ViP4 to customize it as close to the way I had my Incredible set up.
iPhone 4 Pros:
1. Battery Life - talking/texting/e-mailing for a full day is no prob.
2. Beautiful design - it feels like a high-end, luxury watch
3. FaceTime - works great, seamless operation
4. Better reception on the iPhone. There are numerous areas in my neighborhood where my Incredible had a very weak signal. The iPhone delivers clear calls that do not drop out. Calls connect much faster to the network than the Inc.
5. Truly delivers the overall Apple experience - I have been a longtime user of MAC computers and love the little touches built-in to the iPhone. For instance, the "woosh" jet fighter tone that alerts you that an e-mail has been sent successfully.
6. The sheer volume of apps - no contest vs. Android Market. Plus, the apps work seamlessly with the OS.
Droid Incredible Pros:
1. Ability to swap in another battery
2. Browser/Flash support - web-browsing experience is great
3. Snapdragon processor is very fast; response is very snappy
4. Widgets
5. The Google Suite of applications - integrated maps/navigation (best avail., hands down), threaded messages capability if you use Gmail.
6. LED notification light
7. Ability to customize just about every setting on the phone
8. Live wallpapers - a novelty, but still fun nevertheless
9. Adding attachments to e-mail messages are much easier with the Android OS.
iPhone4 Cons:
1.) I miss the haptic feedback (keys that vibrate when pressed) on my Incredible. It really helps when typing on a touch screen. There is a jailbreak app called "Haptic Pro," which I installed, but it's not the same as having it built-in from the factory.
2.) The iPhone is a bit heavier, ~0.6g heavier than the Inc.
3.) The iPhone's vibrate motor is much weaker than the Inc.
4.) It may be a minor thing for most people, but I really like/miss the optical joystick on the Inc., it allows you to precisely navigate to the spot you want when typing/editing.
5.) Jailbreaking and downloading apps to customize the phone is time-consuming. Many of the notification options (custom ringtones, SMS alerts, e-mail tones) are easily customizable right out of the box with an Android phone.
These are just initial observations from someone who is a big fan of the Android OS. However, I am leaning towards keeping my iPhone because the reception/signal strength is so much better (at least in my area) than my Inc.
I will continue to put the iPhone through its paces for 6 more days before deciding whether to keep or return. I really want to love it because of the seamless integration with my other Apple devices......