Hi Dennis
I have spent a bit of time doing low level stuff in the 500 and to be honest I couldn't think of a better tool for it. Mainly around power lines and fires if that is relevant. Talking to the more experienced 500 drivers and maintenance people they have all talked about when in the rare event the donk does go quiet it is probably one of the best machines to be in. I have been told on many occasion by the guys that work on them that the 250 - C20b is one of the most reliable turbines out there.
Hope this helps
Steve