Tomorrow I will be receiving my 4th Droid.
Droid 1 (purchased at launch) - Camera was not functional, screen wobbled. - Phone was replaced next day.
Droid 2 - Incredibly bad screen wobble when the screen was slid open (from day 1 of owning the phone), camera had that awful purple hue in the center of the pictures, 4 soft keys were all different shades of purple, when the screen wasn't open there was an awful click sound coming from the top left corner which was rather annoying.
Droid 3 - Incredibly bad screen wobble when the screen was slid open (after having the Droid for 2 months), purple hue in the center of the pictures, the 4 soft keys are 4 different colors, the battery cover no longer stays on the majority of the time and the space bar sticks (I text a lot).
Droid 4 - Phone will be arriving tomorrow. The guy on tech support told me all of my issues were rather common and it only took a couple minutes for him to send me another Droid. He said if there are problems with this one that they will work on getting me a different device.
I've had no issues with calls or GPS, both have worked fantastically well.