I use a r3xl on my p320 legions. 22k on one, 5k on another. Before that I probably had 30k on some r3maxs. I’ve had zero issues, that said I’ve talked to others that have had issues, most common seems to be the L R adjusmtent screw not holding zero, I’ve also heard of some dying right out of the box or shortly after.
every dot is gonna have issues, but it seems if you make it to 5k you are gtg.