SAS
I think you will find that your PT6 uses considerably more fuel (kg, litres, whichever) per HP than an old Lyco. Small turbines are powerful for their weight but like your 14000 rpm Yamaha they are not fuel efficient.
This is why when people do piston-turbine conversions they find their range has dropped about 1/3.
One can reduce the difference by flying at 25k+ feet but even there a turbocharged piston would deliver more HP per fuel flow than a PT6.
But turbines are great. A single turbine is several times less likely to have to land due to engine failure than a piston twin.
If I had loads of money (a million or so spare) I would buy a single unpressurised turboprop. It would do everything my present SEP does, go a bit faster, use less takeoff distance.
It would drink a lot more fuel per mile but the fuel is (presently!) tax free which more than compensates, and it is available throughout the world.
However when one looks at the very expensive maintenance (HSIs etc), of turbines one probably spends one's fuel cost savings entirely on the turbine maintenance.
Nobody has yet found a way of making a turbine at a low enough price for GA piston replacement. The money isn't there in GA and even if there was, most people would not pay the premium for the reliability. Those that will pay it, can have it already: your King Air, TBM700, various small turboprops, etc