Yes, I had good service along interstates, in cities and even small towns in the boonies. The only problem I had on that entire cross-country trip I did back in '08 was in the remote national parks, where there is no wireless receptivity for phones, TV or internet. Otherwise, the connection was always very good. Here at home is the only place I have a really low signal.
Newly
PS The $60/mo Sprint charged me was based on a 2-yr contract. Virgin Mobile is $40 without a contract. VM also offers the sale of a limited amount of data download for, I think, about $10. Check their website for more info. . .