Might that little company have been Alltel?
I have used Net10 prepaid for about seven (7) years, and I've been happy with it. I buy a 300 minute/60 day card approximately every other month for about $33 after taxes and fees. I don't use it a lot and have accumulated over 8000 minutes. I've been using the same old fashioned Nokia phone for the entire time. It is registered with AT&T (uses AT&T voicemail system and appears like an AT&T phone to AT&T customers). There is one spot I visit yearly in the southeast corner of Kansas where I have a hard time getting a signal indoors. Otherwise coverage has been good. I believe there's a chance your phone may register as a T-Mobile phone, too.
The downside is that you have to buy and use one of their proprietary phones unless you want to pay $50 monthly for their "bring your own phone" unlimited plan.
If I had to do it over, I might have gone with a T-Mobile prepaid plan. You can use their prepaid SIM in any T-Mobile or unlocked GSM phone. My parents use T-Mobile prepaid phones and haven't complained. If you use as few minutes as me, you can buy a 1 year/1000 minute card for $100. I don't think T-Mobile coverage is quite as good, though.
My research has focused entirely on voice and text. If you think you might want to use data, you may come to a totally different conclusion regarding bang for the buck.