All the same problems as leaving it in the truck bed. Maybe even worse if you use a storage facility. I don't, we park it at home, but I still would not want it hanging out back all the time. It would be a little easier to load though, so the idea has that going for it.
It's all just theory for me anyway, since we don't camp where we would need A/C, and we don't even have the companion unit, plus our solar supplies everything we need. But I really like having the small 2k genny out of sight/out of mind in the basement.