I posted the following in another thread. Am adding it to this thread in case someone picks up one of these bolt guns and would like to try it.
If you take the short rear scope mount that came with the gun, turn it around and install it with the vertical part flush with the back of the receiver it makes a excellent perch to place your thumb while cocking. Much, much easier to use.
Still shooting mine - its great. Love the 6 position power valve. Allows me to shoot a wide variety of pellets with a fairly large velocity range for different applications. I have been able to get good accuracy at different power levels without any addditional adjustments (hammer spring, etc.). Just set the power level I want and find the right pellet.