The only problem I have ever had with my 4040 is that when it has new springs it won't cycle lighter reloaded plinking rounds. After about 100 round of factory ammo in my pistol, I tried it again and everything worked perfectly. It cycles factory (both plinking and the self defense loads and my reloads) just fine. Some people will complain about the felt recoil of this gun being a little too much, but recoil is really a matter of taste, and it doesn't bother me.
I forgot to add that it only has its safety on the left side of the gun. If you shoot left handed this could be an issue. Also, magazines can be difficult to find.
You know what, these pistols aren't worth your time, just gather them all together and send them to me so I can rid the world of the 4040PD threat
No, really, these are great little guns, you can't go wrong with them.