I have operated a PT6-15, PT6-34, and the PT6-60. All of them were great engines. Very expensive to a small operator. The last one I bought was the -60 and the engine was $355,000! That was in 1998, I am sure they are around $450,000 by now. That being said, The first P&W Turbine that I owned was the -15. Took the old P&W radial off and stuck the turbine on. Increased the production on the same airframe by around 75%. Lots less "downtime" with the turbine. Pretty economical to operate. Really not much as far as maintanance, just cleaned the nozzles and filters every 100 hrs., nozzles, filters,and compressor wash every 300 hrs. Hot section about every 1500-1800 hrs. I think the P&W turbines are some of the finest engines ever built. If I were to go back in business tomorrow, A P&W would be on the nose of whatever airframe I bought.