Tac, I also have a 604 and quite like its simplicity and shape, but it is let down by the power output. I like my air pistols to be launching a 7 grn pellet at 450 to 550 fps and the FAS struggles to get 400. This is only my personal preference as we use air pistols at quite long range at our club. Many on here will say 400 fps is fine. I have the Airmatch 600 which is like an extended 604 and gives better performance but is then losing its real firearm similarity. I was trying to think what powder burner I would like copied and I think it would be a PCP copy of the Thompson Contender in .30 calibre airgun pellet. We have something available all ready in the 8mm Giffard pistol, but being an antique at £2500 not readily accessible to us all !
Baz