Things I liked: Good looking rifle, easy cocking, very smooth and precise operation. Light weight for its power, great for hunting and offhand shooting. Mine is .20 cal. and very accurate using the 14.3 gr Benjamin Diablo pellets I had on hand. Quality, handling and accuracy were primary factors in choosing this gun and I am very pleased on all three counts.
Things I would have changed: All said, nothing. It would be nice if the safety did not set automatically, and could be simply set and reset, but that's not a big deal - just adjusting my habits. The trigger is excellent and certainly enables accurate shooting, but it is quite different from the single stage triggers I'm accustomed to on centerfire rifles. I prefer the crisp break without take-up on the firearms, but the take-up on the Beeman probably makes me a better shot because it reminds me to hold it like an air rifle.
What others should know: I mounted a Leupold 3x9x33 EFR scope with Beeman 2-piece medium height mounts, which looks and works great on this gun. The R9 shoots well enough that you're unlikely to realize its capabilities with low quality optics. After shooting about 50 pellets to sight in and then determine trajectory at various ranges, I set up targets to check accuracy. Using a rest, at 25 yards the rifle puts 5 Benjamin pellets into as many 1/2" groups as I care to shoot. From a field sitting position I'm getting 10 shot groups under 1" at 35 yards. I've since cleanly dispatched a half dozen rabbits at ranges from 39 to 53 yards. These pellets are a bit of a loose fit in the breech, so I suspect they may not be the most accurate for this rifle. I just acquired a selection of pellets and will begin testing when the weather warms some. If accuracy improves with break-in or a different pellet or me getting more comfortable with the gun, that will be great. But as it is, I'm completely satisfied with the Beeman.