Yes, the commercial operators here in Juneau have removed all the IO-550-F models. There's no comparison in reliability and performance between any other engine and the IO-550-N. They say the -N is 310 horsepower but you'll think it's a lot more.
I think the -F models should be discontinued. The cylinders wearing out or cracking on floatplanes is common place, especially amphibs.
Klaus Marx - Piper Pacer Pilot
Juneau, AK & Wenatchee, WA . . . . . . Click on Link Bar to view the 'non-profit' group.