T-Mobile ended up exempting speedtests from their data caps. Reason being, the employees used to be locked to a cap without the option to get unlimited like the customers have. As they rolled out LTE, the employees were testing all the time and burning through their allowance quickly.

I'm looking into the differences between LTE and HSPA, driven by the exposure the last job gave me into cellular radios. So much of the basic signaling has changed that measuring "good" signal strength is quite a bit different. LTE handles interference in a better way. It's a good advance in the radio tech to help support more and more devices out in the wild together.

I'm eager to also see the changeover to Voice over LTE (VoLTE) as it brings a little more bandwidth for higher quality calls. US providers seem to be experimenting with it across a small number of phones and markets currently.

20mbit on HSPA+ is really good, and right near the cap of what that spec is capable of. 42mbit hints the LTE is the first generation. The ~90mbit from my tests hints at LTE-Advanced, what was initially deemed the proper 4G transition point. Verizon here in the US is calling it XLTE.