No need to beat a dead horse.
-Both guns need new sights out of the box to be serviceable
-Glock goes not need its internals so much as touched to be serviceable. Buying an M&P is buying a defective , parts kit that requires after-market parts to make even remotely serviceable, and still is inferior to glock.
-I could care less what your department uses. Police departments are notorious for piss poor testing as they usualy don't have the budget nor internal expertise to properly evaluate a weapon. Hence why so many just adopt whatever the FBI use because they actually do real controlled testing. Not the police chief getting kickbacks and his brother cousin putting a case of ammo though one or two samples and calling it good.
-Lots of agencies do not provide weapons. Officer purchases make up the vast majority of M&P and XD sidearms out there.
-Glock prices have been the same for 30 years. Smith has to slash their prices + offer cash rebates just to get the masses to buy their junk.
-Duty guns should require nothing other than new sights and a change of grip for the shooter if they are modular. Dicking with internals, springs, after market parts ect generally makes the weapon more unreliable. Smith actually defied the odds by creating a service pistol that requires after-market to be serviceable. That tells you everything you need to know about their quality.
And no glock didn't just trade them out. Agencies have been dumping them in mass due to piss poor performance when they are actually used. Most that have, just went back to what they used to use, either sigs, glocks or HK's. If Atlanta PD went back to glock because they are in their back yard, then why did they select M&P in the first place? Glock has been in Smryna for decades, why now?
There is a reason the market has been flooded for the last few years with police trade in M&P's. They were going to $200-250 used and still not selling. This dude will sell them for $200 a pop if u buy 3
http://summitgunbroker.com/m-p-40--285.html.
So stop pretending the M&P isn't a colossal piece of shit because it is. The market has reacted. Its no different then the HS2000 which is a Croatian $200 piece of shit re-branded by Springfield. Hell, I own or have owned just about every pistol on the market and still own a half dozen glocks,, M&P's and sigs, despite almost never shooting them anymore. I have a custom M&P with just about every part replaced with something better than stock. And its still a range gun despite being more reliable and accurate than your run of the mill M&P.
IMO The VP9 and PPQ are both superior platforms that give nothing up to glock. But at the end of the day, the glock is the golden standard of reliability and durability. Go out and ask the top trainers in the country, who see dozens of new shooters every week putting 500-1000 rounds through pistols every other day what actually works. A Police office who shoots 2 mags twice a year qualifying is not even shooting enough to know if they are issues. Running lots of samples hard and fast with heavy volume separates the wheat from the chaff.
What if 25% of M&P's are defective, assuming there ins't actual engineering defects that there are. Statistically you would get a gun that you think is fine. Service weapons are like parachutes, you want to jump a chute with a 25% failure rate? If you are , that says a lot more about you than you know.