I have an older Tactical Solutions Upper on a regular AR15 Lower. Pre M&P 15.
Mine runs as well as could be expected with Black Dog Steel Lip Magazines, and Ammunition that it likes, M22 comes to mind.
I just rebuilt it. Off came the M4 Handguards and Military Style Front Sight. Replaced the handguard with a Midwest Industries 15" M-Loc Handguard. I also replaced the Adjustable Butt Stock with a MagPull MOE Rifle Stock, same as on all of my other AR15's. I kept the Carbine Buffer and Spring in the Rifle Extension Tube using a plastic filler spacer. To the Handguard a Added a short section of 1913 rail for a weapon light for Night Shoots. I also added a M-Loc Bipod Stud for a bipod.
I also added a Leupold MK AR Cantilever Scope Base, to which I added an Ultra Dot 6 Red Dot Carbine Sight using scope rings providing a proper 2.6" scope height.
Great set up. I put more ammunition through it than all of my other AR15's combined. I can shoot it till I have a blister on my trigger finger for under $30 ( Old Ammunition Prices
). Never have had a blister, but the point is, it is cheap to shoot a lot.
My brother got on the boat later on, and has an M&P15 that he likes a lot.
Bob R