Two folks in my local NRL22 group started with RPRRs, used them to win, and then moved up to Vudoo/RimX but still have their Rugers, loan them out etc. One has a Shaw barrel, the other is stock and shoots CCI SV beautifully.
Another local expert started with a 457 MTR, stepped up to Vudoo, still has the MTR which is wonderfully accurate.
Can get a replacement chassis for CZ 457 (eg, KRG Bravo), not for RPRR…
Lilja makes aftermarket barrels for both 457 & RPRR.
After getting interested in NRL22 earlier this year and trying a 457 MTR loaner (very nice! If you get a 457 be sure to get an MTR) and trying semi and bolt sporters I already had, I rolled the dice with an RPRR. Beginning to set it up, so far so good (with factory barrel). (Norma Match22, SK Standard+)
RPRR over 457 MTR, because a) the cost of the RPRR plus a Lilja barrel is nearly the same as a CZ 457 MTR, b) the 457 would need a chassis at some point, and c) parts (magazines, etc) for the RPRR appear much easier to find.
Was able to try a friend's new basic Vudoo (with Wolf Match) - smooth & solid feel, super fun - like hitting the easy button.
At some point, perhaps a Vudoo or RimX for me…