Droid is a good phone centric device and works great with Verizon 3G- wish it had Flash now rather than June/July. Still, I am returning Droid and will keep the N900 due to:

1. Keyboard SUCKS and d-pad is a dysfunctional waste of space.
2. SD card blocked by battery
3. Re-encoding videos to play on Droid is time consuming
4. Low app space
5. Not many great apps except what shipped last year and the New Navigator. Tons of Lego-like duplicate apps (due to high level SDK- apps are kind of like lego builds)
6. The camera is weak and not so sure software will fix- lense seems below average and capture speed is slow.

I love the 3G with Verizon though and wish the N900 worked with their service.

Added:

In spite of all of this, the Droid would still be my second choice (for now)- due to Verizon coverage and speed in my area.