I went down this same rabbit hole recently. Decided on the MR762, seemed like the best choice to me. Downside is aftermarket parts can be hard to come by and are expensive. Finding a Geissele ambi charging handle for it was a chore. I haven't taken it to the range yet, so I can't comment on...
Got a great deal on a MR762 on here a few months ago. Found alot of good deals when upgrading as well. Installed the HK quad rail, Geissele trigger, Geissele charging handle, extended trigger guard, G28 stock and buffer tube, ambi endplate sling attatchment, troy backup sights, and a Trijicon...
Besides my j-frames, every gun I carry currently is polymer framed. Would never judge my fathers collection by what sort of frame it had. In fact, I hope the bastard buys a Mark 23 before he goes.