We had VM prepaid for quite a few years. It was one of only two or three services that actually worked in our rural area. Their best phones are reserved for contract customers. I usually bought one of their top-of-the-line prepaid phones, but they tend not to have all of the most recent features and never did last us all that long. Had to replace quite a few.
Over the years the quality of both phones and service seemed to go downhill for us. For example, my dd would call me and my phone wouldn't ring. We started missing more and more calls for similar reasons. Also text messages started getting delayed, sometimes for half a day.
If you need help with your VM service, forget it. They have particularly annoying canned voices answer you, and it can be very difficult figuring out how to talk to someone about a problem.
We finally switched to a T-mobile subscription plan. Costs more, but the service is much more reliable for us. Now my dd's T-mobile phone is acting up, though.