There's definitely a material difference between providers. I'm on Verizon now, but T-Mobile and AT&T were both much better when I had them (and I'll be switching back as soon as I can).
[0]http://arstechnica.com/tech-policy/2016/09/nyc-threatens-to-...
Sadly, I've also been very disappointed with FiOS speeds lately.
Don't trust Verizon. They're a sham company.
With the carrier aggregation now turned on I can get as much as 100 DL / 5 UL. They own the most LTE spectrum.
Verizon does have the best network NYC.
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. http://cellularinsights.com/state-of-lte-advanced/
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...