The safety blocks the trigger bar from moving in the Sear. It does not lock the slide as it does in the Ruger LC-9. My Shield is my first M&P with a safety...my full size and compact do not have one and I prefer it that way. Since I have no option with the Shield I will only use the safety for re-holstering. Once the gun is in the holster I click the safety off making it just like my other M&P's.

Denying yourself ownership of a new and great gun based upon a simple little switch really doesn't make a whole lot of sense to me. Just leave it off and forget about it, problem solved. At least it doesn't have the dreaded key lock like many of the Ruger and Taurus guns.