The company I work for had several of the Novatel 2200 MiFis and recently upgraded all of us to the new Novatel 4510L 4G MiFi devices. One problem that I've noticed is that I cannot find a way to check the data usage directly through my MiFi.
On the old 2200s, you could fire up VZAccess Manager and it would tell you (after you connected) how much data you had used so far on your billing cycle and when your billing cycle ended. VZAccess Manager doesn't work with this model, so that method is out.
I've looked through the user manual and the web interface of the 4510L trying to find anything but came up with nothing. IIRC, the old 2200 actually had a counter in the web interface that had a running count of data usage which you could manually reset (was persistent across connections/boots), but the 4510L doesn't even have this 
I can call/e-mail the employee in charge of these devices for the company and they can logon to the website and tell me the data used, but I don't understand why there isn't a simpler way to do it without bugging someone else. Since all of these devices are on a company account, I don't believe we can all register our own MyVerizon accounts (if I am wrong on this, please let me know how to do it).
So - I'll end with a request for Novatel/Verizon - in a future firmware upgrade, please provide the ability to retrieve current usage. At the very least, bring back the persistant usage counter that I could just reset on the first day of each billing cycle. I know this probably isn't very important to you in the grand scheme of things, but I would sure appreciate it 
-Nick