I do best with all my 5 M&Ps using #3, combat picture. The Novak fiber optic front sight has fallen out twice in my 40 Pro 5", and I finally said enough is enough. I shoot through the hole left in the front sight, which is about as combat sight as you can get. Don't laugh, it works and works well.
To add to the laundry list, I really like Gunzilla, which is a plant based CLP that works. For copper removal the same company makes Copperzilla, which has no ammonia and also works very well. Hard to find in gun stores, but Amazon carries them.
Have you used a bench rest to take the human element out? Maybe even have another shooter who shoots M&Ps well bench rest it. We have 5 M&Ps of various flavors that all shoot dead on.
If you read the contents of gun scrubber, etc. it's the same as non-chlorinated brake cleaner, ~$3 per can at your favorite big box store. Have used it weekly for 3 years on half a dozen polymer firearms with no issues. It does remove the glue used on stick on grips, however.
While I've always cleaned the striker mechanism with aerosol brake cleaner (gun cleaner clone), just for fun I thought after 20,000 rounds it might be time to actually take it out and see how it looked. Short version is not bad at all. A bit of black but not enough to hinder operation. The...
Don't worry, you'll eventually end up with a drawer full of holsters any way you start out. Data point: my favorite IWB design has the two belt clips with a leather shield separating your body from the pistol. Easy to wear all day. Whatever way you go, get one that is specifically made for your...
another new M&P22 data point
Sorry about your issues. We recently bought a M&P22 to go with our M&P9 and M&P40S&W. Have shot 600 rounds, unfortunately no Remington. But, 400 rounds were 45 year old Western Super X yellow box that my dad bought in the 1970's. These had previously not fired well...
My experience has been very good.
After about 15,000 rounds fired, the slide stop broke off on my M&P40 Pro. Called S&W customer service. They emailed a shipping document and returned it fixed in under 3 weeks. No charge to me for anything and they included a 10 round mag for free.
Also later...