Have you tested signal quality in large buildings in Manhattan?
I can say I get signals in these buildings when iPhone owners using say, AT&T get no signal.
I suspect that much of the difference you see might have something to do with your handset.
This report demonstrates that Verizon has the best network.
T-Mobile already had that equipment deployed for over a year in some markets. They also are the only ones running 256QAM DL 64QAM across their entire LTE footprint (though you'd need a phone supporting it) increasing the spectral efficiency 15-20%.
If you can tolerate the boasting typical of a press release this is the CTO of T-Mobile discussing what they have already rolled out: https://newsroom.t-mobile.com/news-and-blogs/lte-advanced.ht...