I'm 65 and have been shooting for many decades. In that time I've own many guns and have ALWAYS regretted selling guns that I like.
I own both M&P's and Glocks and after much stupidity I learned to keep them both. My Glocks have been the most reliable guns I've owned.
I shoot .45 Super in my Glock 21. Changed to extra power recoil spring, fully supported after market barrel and .45 Super brass cases.
Gun shoots well and with this setup I can still shoot normal pressure rounds.