1 GHZ has been reported stable on the long use, I use my phone alot… i also use the GPS a lot and havent had an issue, anything over that gets a little sketchy when your memory starts to run low.
GPS worked fine for me, but there is a fix for the people who have had issues with it, 2.1 is supposed to be comming out in the next week or so for the Droid.
I just got my replacement phone ( my speaker stopped working intermitinly a few weeks ago, I think it was the hard Drop on the ice) so Im just going to O/C for now and wait for 2.1 to come out.
BTW, if you dont have it already, get Advanced Task Killer… Awesome app