I've been pretty impressed by T-Mobile's network performance lately in Long Island. It looks like they're slowly but surely pushing n41 into the suburbs. As a side effect, n71 and LTE performance as a whole have increased quite a bit. I'm assuming this is because T-Mobile is increasing backhaul at a number of sites in anticipation of these n41 upgrades happening.
These are indoor and outdoor n41 speed tests from the same site in Flower Hill/Roslyn, NY on n41. This is eNB 45048 on Cellmapper. It's near a strip of stores that have pretty high foot traffic so the ability to get these speeds is awesome.
I also spent some time in Ronkonkoma and got these speeds indoors on LTE and n71. You can see that the speeds are pretty similar but the main benefit of 5G is the ~15Mbps increase in upload speeds. I beleive this is eNB 42322.