I am in the same non rooted 621 situation. If I ever get the droid x rooted again, I will shut off ota for good. I can not understand why verizon can not detect by ota if the phone is rooted and just leave it that way.
Even Microsoft being the stinkers that they are, gives us a choice to install updates or not and to pick which ones we want. Does this phone belong to us or not! What right does Verizon have to shut out the owners of the equipment from having root. The phone does not belong to them!