I will add my .02 since I have been with sprint 6 years now.
Here is the straight up on sprint. They are in catch up mode no doubt. They gambled on 4G and wimax with Clear. That gamble lost. Wimax is very spotty and LTE will be the standard. Because of this sprint has now had to cough up something like 21 million dollars over the next 2 years to get on board with LTE.
That being said that is all "DATA". There data in 3g is still pretty fast considering and has always been enough for me. Sometimes I win the race, sometimes ATT wins the race, sometimes verizon or tmobile. Just depends on the area.
In terms of voice coverage verizon is #1. However sprint has a roaming agreement with verizon and so if there is a spot sprint doesn't get digital, I roam on verizon. Like Drape I have been hunting in the mountains and made and received calls when ATT and Tmo would not. Snowmobiling as well I have been surprised by the places my phone rings or sends texts. I have never felt lacking for voice coverage.
So summary= Data- good and getting better. Voice- a close second to Verizon. PRICE= no comparison
I honestly feel that for what you get in terms of voice coverage, data speeds, and price they are the best deal out there. If money weren't an issue I would be a verizon customer. I am currently paying $65 for unlimited on my phone. Unlimited text, unlimited data, and 450 min. per month, but with any mobile any time I don't even usually hit half of thos 450 min. because I never call landlines. Everything is cell these days.
Phatty- unfortunately though sprint already capped there hotspot devices. NOT phones, just hotspots.