its too bad, you ran into a problem, glad you got everything working,
i think your initial problem was because verizon changed/re-configured some cell towers, and your old air card didnot have the PRL configuration info.
IF you had re-configured your old card before going to the verizon store, it might have saved you a trip & $52, the good news is the NEW usb modem should be REV A EvDo and give you a faster connection.
Don't remove the vzmgr software, you might need it in the future to update the FW in the modem or to update the PRL file and other configuration info.