Biggest thing will just be if you have decent service where you live/work etc. Biggest complaint I've seen is the coverage, but if you live in an area that is good....
Had Tmobile for years, left for Verizon due to employer discounts. Long story short, I am back with Tmobile.
Can you port your phone with a tmobile sim, or is your phone not compatible with them (not sure what you have now)? Reason for asking - you could "test" out the coverage by just using a sim before breaking service with the other company.I checked their coverage in my zipcode and it says 'excellent' soo I think I am safe?!
T-Mobile FTW! Been a customer for about 8 years.
Their LTE is excellent, service has vastly improved over the past couple years, even the past couple of months i've noticed a big difference in coverage and data speeds/connection.
And just FYI, T-Mobile recently inked a $3B deal with Verizon to buy some of their low frequency spectrum, meaning that T-Mobile's network will work much better over rural areas and inside buildings, which has always been their biggest downside.
Plus, no contracts, early upgrades, etc. they started it all and do it the best in my opinion.