the engine on all the F models, including the FX are a bit tender.
Although I have never owned or flown a piston Enstrom, this is the impression I have formed after talking with those who have. I did own a 480B for a few years and this was a 150% positive experience in every respect. Among many virtues, a superb safety record. I can recommend the 480 without hesitation!
The engine in the 480 is loafing as power is limited to about 300 hp by the transmission (vs engine power rating of 420 hp). My only experience with piston helos is with the R22 & R44, but I think you will find turbine power transformational - relatively smooth, quiet, and reliable. And best of all, the smell of Jet A in the morning!