Last I heard from my barrel making buddy, he'd gotten his hands on a RPR and had rebarreled it in a matter of an hour or so to 6.5x47 Lapua. Haven't heard how it shoots, but will assume that after a few break-in rounds it'll be on it's way to being a real shooter.
If and when I get my hands on one (.243 hopefully) I'll shoot it as is before making any rebarreling decisions. Though I will say that the possibility of taking it out to a 243AI or even rebarreleing to 6x47 (Lapua) has crossed my mind.