Its been 3 full days with my Motorola Pro and so far I'm pretty optimistic about the experience. Battery life is the one gripe that I have- 10 hours with moderate use- but I have decided that I will pick up the extended battery when its available and that should boost it to a satisfactory level.
Here are some of the things I've observed as differences:
1. The screen resolution for the Droid Pro feels....rough. Just not as smooth as the Nexus One or the Galaxy Tab. To be expected for sure, but still...
2. Keyboard on the Droid Pro is fantastic. It felt a bit stiff on the first day but either I got used to it or it loosened up.
3. I do miss the trackball on the Nexus. I never noticed a million different ways that I use it.
4. I don't miss the blinding trackball notifications at night. The notification light on the Droid Pro is much more subtle and doesn't light up the entire bedroom if it goes off at night.
5. Battery intervals: I really don't appreciate the Droid Pro only reporting battery life in increments of 10.
6. Volume: The volume on the Pro is louder and clearer than on the Nexus. At max levels, it doesn't sound tinny at all.
7. Oddities: I've noticed a handful of small odd things on the Pro: Contact images don't show up on my Exchange contacts, BeyondPod installs a khaki colored widget instead of the normal black version. So far nothing earth shattering- just things that make me go 'hmmmm'.
8. Droooooid! I really want to remove that startup sound. If you know how to please let me know.