Hi,
I have an M1S90 and can say I love it, I use it for practical shotgun competitions and I've on had this gun fail on me once. It was totally my fault, I got lazy shouldering it. I run 67mm carts but have also used 70mm, I tend to stick with 32g loads and this works great for dropping the steels, poppers & frangible targets.
It'll run with 26g as well but really doesn't like any lower, I have kept it as solid stock, because I have heard the nightmares people have had one pistol grips.
I have also used this weapon for skeet/clay and it worked reall well.
I love my M1S90, it's 12g and as a very short female shooter it's given me no problems at all. I also have a kickeez butt on it which works really well.
Good luck.
Anna
London, United Kingdom