I’m in Kansas City where we have LTE. I have also switched from Verizon. I purchased the Nexus 4 directly from Google on the $30 pay as you go plan from T-Mobile.
The bullets:
T-Mobile coverage isn’t as good as Verizon, but Verizon isn’t worth the extra monthly expense IMO.
Not having LTE on the N4 does stink a bit, but I get 9Mbps down at home which seems good enough.
I did test T-Mobile’s LTE at the store on an iPhone 5 and the download was similar to Verizon. Verizon’s upload was much better (again, not sure I care because V is so much more expensive).