I started out shooting my MP40 with the medium backstrap and have found since, the large size works better for me. The trigger is (I hear) a 6.5 lb pull. A lot of people judge the feel of the trigger by handling one at a gun store and just pulling on the trigger. That way it is gritty, but, when it is cocked it is very smooth.
We also own a Baby Desert Eagle 9mm, with a 4lb pull that is very sweet but it has a external safety.
Anyway to each his own. Hope I didn't come off as too grouchy.