Go to planequest.com and then the operating costs. Compare a Cessna 425 (PT6) to the Cessna 441 (Garretts). That can give some perspective.
I used to fly both the 425 and the 441 (slightly bigger airframe). Much preferred the 425. Engines were more responsive. There were also several 441's lost due to engine fires, which always stuck in my head, causing me to watch ITT's a lot more than I ever did on the PT6.
I think you might be incorrect about the engine fire reference. There was a metro that had a brake fire that, due to it location when retracted, took out the whole nacelle...but there has never been an inflight engine fire of a tpe331 that i know of..anyone have an NTSB to clarify?
As for power i remember working the numbers while waiting (that is what a pilots real job is) and the TPE331-10 is 13 or 14% for efficient per hp than a pt6 in flight
shoot..I just notice how old a thread this is....