We have had ours for 9-10 months. Took it on a 5 week 6000+ mile trip last Summer and several shorter week long trips. No problems. Since we use pay as you go cell phones we tend not to over use them, just when portability is needed. We didn't leave it on when we were on the road. We just turned it on to check voice mail and make any calls we needed to do once we setup camp. Several friends that called, that didn't know our travel plans, called and left a message to see if we could do something. We would call them back and tell them we were 2000 miles away so we would have to pass. Was handy having our home number along.
We went for it primarily because we already have the house wired with a phone in every room, sometimes 2, plus my shop. This allows us full access everywhere and not have to carry a cell phone around like we would have to if we just moved the number to a cell. Add to that the $25/month it costs for unlimited long distance, with all the other bells and whistles and it was a no brainer. More than cut our home phone costs in 1/2. Digging through my junk I found an adapter from some old retired electronics with the right plug on it and it plugged in to the 12 volt system in the camper for charging when needed. Most nights we just turned it on and ran it off the internal battery.