I have a K-40 and is one of the nicest trigger pulls you'll feel for an out of the box gun, it's also pretty accurate for such a small barrel.
Only thing I found wrong is the way the trigger is attached to the disconnector, when you take the grips off be very careful in not to twist the disconnector, if you do there is a plastic spacer with a spring around it at the trigger which will snap in two, this spacer keeps the disconnector in place at the trigger, it's next to impossible to drift the trigger pin out to replace the spacer without a press and three hands.
I broke mine and had to order a replacement, then I had a friend mill me a copy out of stainless steel, which is the way it should have been made to begin with, now I don't have to worry about this ever happening again.
Would I buy another one ? in a heartbeat if I found it for under $500, it's a great gun.