I cannot really comment on the engines, but the Cheyenne (1) I flew a little while back seemed a bit unstable compared to the King Air. The reason I remember is that the CAA did not like the Cheyenne I when Piper wanted to certify it in the UK.
The only other thing regarding PT-6 operation is that you have to watch out for visible moisture and a temperature range around freezing. That's one of the differences between piston and turboprop/jet flying. We actually had a power turbine blade damage (just one blade) whether it resulted from flying in cold and moist weather (=ice) I don't know.