I own copies of all of the guns noted below. My observations are from actual ownership, not from reading a web site !
1. - 6004 FAS . Yes, it is low power, but very accurate, Easy to cock, nice trigger (adjustable). Nice target type grip.
Have had it a little over a year, and no trouble at all. Not easily adaptable to add-on sights
2. - Beeman P1, like the FAS is nice also. Heavier, but similar in many ways. Though it a bit heavier "duty" also. Able to take some rough handling without damage. Sorta like a Colt, Government .45 look to it. Will even use the same grip panels. A little higher power than the 6004 FAS. Easy to add on other sights.
Again, zero problems.
3. - Weihrauch HW45 is a lot like the Beeman P1, in many ways. Construction, handling, trigger, cocking etc, much like the P1.
Again, same look at the Government .45. Three colors available, black, sand (sorta gold), and a silver color. Also, a little higher power than the 6004 FAS. Also, easy to addon other sights.
Zero problems.
4. - Another, more inexpensive gun for "plinking" is the Umarex, Buckmaster. It's a copy of the Browning Buckmaster. Simple in design, cocks easy, but the trigger is a hard pull, (no way of really fixing it), but once you get used to is, it's pretty accurate. It's a very inexpensive gun.
Not in any way the same class as the FAS 6004, the P1 or the HW45.
5. - Many like the Beeman P17. Me, the trigger on mine is horrible. I've had it apart three times to do modifications to the trigger. I managed to get it much better, but it's still a LONG way from my liking. The FAS 6004's trigger a "world" better trigger, but the P17, like the Buckmaster is VERY cheap.
Also, not in any way, shape or form, the same class as the 6004 FAS or the P1 or the HW45 above.
There's also, the Weihrauch HW75 is more like the 6004 FAS design, power wise. I don't own one, but it's sort of a cross between the 6004 FAS and the P1, in way the gun works. It's easier to cock than the P1 and the HW45. More like the 6004 FAS. Easy to add on other sights.
Have fun...
Mike