While I dont have the FG8 only the FG7, the M388 keybed is the same on SV-1. I find this to be great for piano and electric Piano sounds, but a real pain with synth and organ sounds. I've been playing non-weighted keys for so long, the weighted keys tend slow down my playing and they are more forgiving for sloppy finger techniques.
I do find it hard to compensate for key force when jumping around -- After play a weighted version for a while, I'll tend to get extreme (127) velocities on the non or semi-weighted keybeds. And when I move the other way, I'll have extremely low velocities (0 to 65).
Here again I prefer non or semi weighted keys as I have better velocity control and faster finger motion.
Fantom G & X7, Motif XS6, M3, V-synth, JP8000, M1, Wavestation, Radias, Nord Lead 2X, Karma, Snow, electribes and other groove boxes.