Just completed a 10-hour trip using Google's new Navigation that I downloaded to my Droid Wednesday night before I left (ver 4210). A big step for me as I have traveled with a Magellan Roadmate for over three years. Maggie and I logged thousands of miles for business and high school sports. She detoured me around traffic, got me to obscure hockey rinks and -- bonus -- proved my husband wrong a time or two. But he and I were going opposite directions at the same time, so I volunteered to let him have the Magellan and I would test my Droid's GPS and Google.
I traveled through three states, urban, suburban, rural and marine (ferry from Connecticut to Long Island), and never lost a signal. Worked without a glitch both ways (5 hours each way).
Here's my comparisons (not in a car dock - see pix and explanation below):
voice quality - about the same
screen quality - Droid crisper; better contrast.
Features - I missed the estimated arrival time that is a feature of Magellan. I like the turn info on Navigation. Two turns on screen let's you plan ahead. Big battery hog - I started with a 100 percent battery, had it plugged in to my accessory socket, and it still drained some battery.
Phone rings through and takes precedence over Navigation. Not sure if that is good or bad.
Just like Magellan, you get a 2 mile and 1/2 mile warning of an upcoming turn. Magellan warns you to stay the course as you pass major interchanges - Navigation does not.
My Droid wears an sapphire blue Seido Innocase. Can't afford the Seido car dock yet. So-o-o-o, I took the useless car dock they sold me at Verizon, and turned the holder to a vertical position, then strapped my Droid to that with rubber bands (see photo). Top of the line Droid held up with rubber bands!! Classy, huh? (and no, I don't keep my Christmas lights up all year). Obviously, the magnet doesn't engage as it doesn't line up, so I just clicked the car home widget before I started. Worked for the entire roundtrip! Didn't slip, and I moved the rubber bands around so as not to interfere with the important onscreen sections of the Navigation.
So - bottom line - I feel more than comfortable running with the Droid and letting Maggie stay with my husband.