ssh looks really great on the Droid's screen-- I can have an 80-column display. This is a huge win for me.
The email app on the Droid sucks big hairy gorilla balls. The biggest problem I have with it is that there's no way to delete all messages-- you have to either delete them one at a time, or tap each one to star it and then delete the whole group. This sucks even more than it sounds like it does. What the fsck were they thinking?
Having dedicated-GPS-style voice navigation on my phone is hugely useful. It's clear that this is a 1.0 release, and the software could definitely stand some improvements, but having something that's 80% as good as my Garmin but is with me at all times is absolutely wonderful. My biggest issue with the driving directions is that it sometimes gives instructions too late or almost too late. I've seen this several times, but the biggest one is heading home for me. The route home involves taking the curve from 980 to 880 south, then just as you exit the curve taking the Jackson exit. Google maps inevitably tells me to take the Jackson exit about three seconds before it's too late. It seems like the instructions are so busy telling you to get onto 880 (which you can't avoid doing) that it isn't prepared to tell you about the next big thing that's coming up.
My Garmin will often say, "Turn left at FooBar Street, then turn left." Google nav will say, "Turn left at FooBar Street", then wait 'til you're pretty close to the next turn before warning you about it. On the other hand, it's cool that the screen shows you street view images. I don't see them much, since I'm paying attention to the road and just listening to the voice, but it's a cool idea.
The voice is mechanical. I don't find that annoying, but I can see how some people would.
I just realized... I wonder how well navigation works if you're outside of cell range. I don't know how much pre-caching it does of maps, routes, etc.
Battery life is pretty decent for a high-end smartphone. The screen sucks batteries pretty badly, but I expected that. I plug it in when I'm navigating in the car but otherwise only at night, and I usually have 60% battery life left each evening.