The Romeo3 Max and XL hold up better (not super great though) on a frame mounted optic. Slide mounted I’ve seen at least a dozen die right away. RTS2 will do better on a slide.
Weigh the costs of each. With the Scorpion it will run 100% with any ammo (that’s my experience). Fit, finish, and quality is amazing. You won’t get that with a Franken build right off the bat.
I should’ve said this the first time I posted on this thread but I have never had an issue with my MBX magazines. They seem to work in any gun I have owned. For my SV guns I use SV mags though.