Nighthawk MR1100 -- Yes you can unlock on AT&T

Hmmm, I don't recall exactly what day or number I called.  I believe it was a snow day here in the Northeast.  I tried to submit the request online, but the webform validation failed on the IMEI.  There might have been a phone number at the bottom of the screen or I just browsed to the main AT&T support number on their website.  I likely called mid morning, during the week (M-F).  I definately got an American (Southern).  She was very nice but not very helpful.  I was persistent in explaining my issue (using technical jargon) and after ~10min of trying to help me re-do what I had already done and failed (web submission) she put me through to Tier-2.  Tier 2 was also very nice, she listened carefully, understood what I wanted.  She, herself, wasn't able to do what I needed, but she created a case for the request.

I recently tried to unlock my new AT&T (ZTE) Velocity 2.  So far this has not been going as well.  I was able to submit the online form.  But then I got a failure email about an hour later saying that the IMEI I had entered was incorrect (it was not) and that there was no such AT&T device.  I bought my Velocity 2 from AT&T.com  I haven't yet tried to call and follow up.

I have another Hotspot with T-mobile (ZTE different model).  They're even more of a mess.  I've been working on it with them for more than a month.  Two phone calls, two emails.  B.S. about having to contact the MFG directly on my behalf to get the unlock code.

I don't know why carriers make this so hard.  Apple has it right, one unlocked device to rule them all.