I have a Gen 1 45 that I SBRed. I love it, have at least 500 rds thru it, mostly suppressed. SGM 30+ rd mags work well, but those cheap ass Korean ones don't. Easy to install the mag extensions on a factory G21 mag.
One thing to be careful of, it likes to be clean before shooting suppressed
. Main issues I've had was using dirty ammo while suppressed, then I didn't clean it before going shooting with it months later
. Not as forgiving in that regard as a Glock.
One major dislike I have is the sights. I bought mine used with mbus sights on it, and those as well as the factory ones are too high for the slowpoke .45acp. I bought some MP7 takeoffs that work great because even folded they have a post/notch set-up. brings the sightline closer to the bore-axis.
And I also agree with the poster above who mentioned the PS90 and the Kriss as the most fun to shoot.