Straighttalk can be AT&T or Verizon. The phone you buy or plan to use will determine which network you will be on. If you look at the phone box in the store and it has a red coverage map, then it will be verizon, blue coverage map is At&t.
AT&T - You will get LTE speed
Verizon - You will only get 3g. If they ever change to 4g I will go back to the verizon side
I had the verizon side and like the phone coverage but the 3g was a little slow. I swapped to the At&t side so I could get LTE and it is a good bit faster. Coverage seems good in most of the places I go that are off the beaten path.
If you get in a busy place with a lot of people and the ATT or Verizon network is at capacity, you will get booted before the real customers do. Last time I was at the Georgia dome my data was extremely slow due to the load on the network. Occasionally you will drop a call when you have full signal. Other than that it is pretty good. Customer service is horrible in the rare circumstance you need them.
If phone is you primary concern, I would look at Family Mobile at Walmart. You will have to be ok with T-mobile coverage. It is probably the best deal around these days.
