Ripping the pin out of a low cap long magazine is stupid.
The low cap mags don't have the button necessary to push the follower down while loading it to capacity, which makes it a real pain in the ass to load.
If you want to own an illegal standard capacity mag for your M&P 15/22 then drive 45 minutes to New Hampshire and buy one.
For what its worth, I really like the short 10 round mags.
Re the 10/22 vs M&P 15/22.
I consider the 10/22 to be more of a gun to be tweaked and customized. You can build a super accurate gun that will rival an Anschutz. You can build a race gun. Or anything in between.
The M&P is accurate enough. But its great because it allows you to do all the manipulation you would do on a regular AR while shooitng. 22 bullets.
I made Rifleman with an M&P 15 at an Appleseed once. So I was shooting 4 moa with standard magpul mbus sights that come with it.
Don
The guy i saw with his pins drilled out had no difficulty loading his mags... it didn't look like the mag spring was exceptionally strong.