Depends on where you live, T-mobile is good around my area in NJ. At $70 for unlimited talk/text and data and $20 for phone payment your paying $90 for unlimited everything. You won't get that price from Verizon or AT&T and you won't get that speed from Sprint.
Get a little smarter and buy your phone elsewhere, get a nexus at half the price or phones on sale on ebay and it's an even better deal