Rick, just wondering if Bill RugEr might be doing a few barrel rolls in his grave over this thread, with Bren's unusual comments about the typically superb 22/45.
Well, in my opinion, Willy B. Ruger pooped the bed on the 22/45. I've shot and liked the Mk II in various incarnations, the Mk III Target and Hunter, the 10/22 & 10/17, the Mini-14, the GP-100 series (some day I'll probably own a GP-161) and the P90 (actually, it was the stainless KP90). But everyone has a misstep occasionally - I believe Ruger did with the 22/45 series.
I don't really "get" a pistol that combines the chunky and clunkiness of a service pistol with the lack of power of the .22LR cartridge, y'know?
Like putting a 1.2 L engine in a Town Car and marketing it as "all the awkward handling of a land yacht with the lack of power of a subcompact"...
You like it, and that's cool... more power to you - I really don't... to the point that I have a strong opinion against it...
As for the aftermarket magazine disconnect parts, you can just remove it and make up a brass shim to take up its place on the hammer pin, slip a hammer shim between it and the hammer to minimize soft metal to metal contact and you'd be golden.