Have had a 24" Puma for over 6 years (bought it used) and they are pretty solid plotters, It runs on average of 4 hours a day 5 days week.
The main board went out on it 4-5 years ago disabling one of the drive motors. The board was fairly inexpensive and spare parts are still available for these. Knock on wood that plotter should last us a while longer. If/when it needs to be upgraded it would be replace with another Graphtec, we love our FC 8000.