I have 7 Mitsubishi outside units connected to 17 indoor units on a boat and they are on generator power 100%. In 6 years I have had 1 compressor failure, 1 indoor unit failure and a couple of failed circuit boards. I believe this is fantastic considering the vibration, extreme temps, and dirty power supply they operate under. We were struck by lightning about 6 months ago and while we lost radios, radar, and a fridge none of the ac units were affected.
The only negative comment i have is cleaning the squirrel cage blowers on the indoor units sucks. Also, remove the covers on the outside units every 6 months if unit is ran a lot and wash out condenser with a garden hose.