Normally I don't post but I found this thread very intresting. You just don't see any negative feedback on the S&W M&P 15 22 at all. I own a S&W 15-22 myself. I have had it about 2 months and had nothing but bad LUCK, it seems.
Before someone responds, please finish reading this.
I have spared no expense trying to get it to work with a Slide Fire stock. I still do not have it working 100% without some FTF and ligth strikes.
However, if I use it as it was orginally designed , I have had absolutely zero problems ( with the Slide Fire in the locked position ).
I have a Timeny 3 lb.triger, replacement springs, Frog Lube, Tach Ammo, etc. I have had at least 5 other people try to fire the Slide Fire with the same results, including a gun smith.
So there can be problems with any brand. But I will keep my 15-22, as I have had many componets to try since it will interchange alot of AR parts.
If I had chosen another brand, I would have given up by now, sold it and put what extra parts I could on Ebay. I think this says alot for the M&P.
Just my 2 cents, worth.