I have the same Amzer mount and use it all the time with my Droid 2; HOWEVER, people here need to know something important about this mount. The mount is in two pieces and one slides into the other and is supposed to lock. Under hard use, the mount can separate and your phone will go flying.
I had it happen to my phone going over some railroad tracks at 25mph. The phone FLEW down the road and fortunately chipped up small portions of the bevel but didn't scratch the face.
To fix it and ensure it doesn't happen again, I got some polystyrene glue to weld the plastic pieces together. Now it seems completely stable.