Don't bother with the CEl-Fi option either, adds another 2 yrs to your contract:
Rather a sad update. After a while with T-Mobile, they will not budge at all.
They said to me:
"We would rather loose you as a customer than give you this $500 device for free."
The support tech was really polite, but the fact remains, if you get cell reception in your attic but not in your living room, and T-Mobile has a device that makes you able to use your phone in your living area, they are not willing to give it to you for free, such that you may be really happy with them and keep their service.
I bought the new Wilson device from Amazon, at $300, considerably cheaper and no contract extension. Not sure I will be a T-Mobile customer for the foreseeable future.