Well all i can say is that I run 3 x schweizers at my school here in Devon and they seem to stay in the air quite well. Example
one machine been away for 1 year and 300 hours ( leased to an hour builder)
Only unscheduled maintenance was one starter motor ( quality of todays is crap) and a mixture cable. All the rest was scheduled checks or part replacement.
The other 2 seem to be good, can only speak as I find