Loved my FS8. It was quieter than my dm6 with similar shot quality. I've had b2ks, gen 1, 2 freestyles before and the one issue I had with these is the small trigger guard. It is not 6'3" ape finger friendly. The quest had no where near the sound or shot quality, but trigger was sweet.
The frame size and fsdo were the only things to flaw that fine FS8. The older ones needed some tinkering skills. The 8 was as simple as a matrix to rebuild and lube. Stock regs on icd markers can be made consistent by drilling a couple simple holes.
I think there are better options for the $$ than either, but if your dead set on these then reread post #3.