Things I liked: perfect for an air rifle out to 20 yds or so, easy to mount and easily adjustable. I found the red dot bright enough in summer sun, depends on target color really (white target not as easy to see). Has a nice look on the rifles, not heavy and wont bounce around.
Things I would have changed: I see a common theme here...auto-shut off BSA. Also, I would add crosshairs to easily line up shots as a refrence point for the dot, for now you have to "guess" each time you shoulder the rifle until muscle memory kicks in. I'm surprised though, within 100 rounds I'm on bullseye @ 10m consistently as I use the front rifle sight to give me a reference for the dot.
What others should know: still a great sight and (for my range) very effective on my Mendoza 600 .22 and my AirForce talon 22 .177. Can still shoot 20m groups w/n .5-1". Use Threadlock on the mounts once sight is in place.
Things I liked: Power and accuracy are phenomenal. I wouldnt have bought my Mendoza RM600 .22 if I had known about this one. Bought this in .177 and am ordering the 24" .22 barrel later. No recoil, you can see the pellet fly through the hit zone in the scope - how cool is that! It's a one-hole puncher @ 10-15 yards, seriously accurate.
Things I would have changed: I really wish it had a pressure gauge built in so you could see what operating pressure you're at. Without a chrono you really have to guess, "if I blast through a steel can @ 15 yards, then it "should" kill that squirell, right?". Was a LOT more money than I thought I'd ever spend on an airgun, but I can shoot all day in my yard and not freak out neighbors.
What others should know: I've blown through 1250 Crossman Premiers and it never gets dull. I do wish shouldering the rifle were easier - the round tank isn't exactly a face plate, but you get used to it and the pistol grip really aids in stabilizing for shots. You will love this gun, even after you've regretted paying for it, and the pump, and the scuba tank, and pellets, and targets, and.... :)