You're not wrong, FM9 is fantastic in 4cm with an amp. BUT... The FX8 (and the Line 6 HX Effects) are MADE to be effects only and are automatically unity gain. There was no volume knob. No fiddling with output levels and such. FX8 had a magical path selector thingy where it would place things in parallel or other configurations you chose and automatically do kill dry, blah blah blah. Just pure simple effects magic

The ONLY reason I got rid of mine is because of my stupid gear addiction and feeling that it was one generation "behind" the quality of Axe FX III effects. So I will buy a new effects only Fractal item in a freaking heartbeat to use with my tube amps and Friedman preamp pedals.