S&W has a M&P tune up gunsmithing package that you can get for $105, that includes the Performance Sear that is included in the Pro model. They also do a number of other things to enhance the gun.
Just check their website under the Performance Center. If you cannot be without the gun, for $130 they will guarantee turnaround in only 5 days, including shipping time.
So you could always add that upgrade to the gun down the road, if you wanted to.
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