I you reload the ammo after you shoot the OBR, you may be better off with non-Xtran.
If you toss your brass after a shooting session, then it should not matter much.
I have not had any brass longevity issues with my XTRAXN OBR. It does leave carbon marks on the brass that suggest light fluting, but the brass tumbles clean and there are no ridges or lines that can be felt on the cases. Here's a thread from a few years ago, there may be some useful info in there for you ----http://www.snipershide.com/shooting...obrs-fluted-chamber-xretardn-whats-point.html
Assuming you're buying used? The pre-xtraxn rifle may have more value long term because there are less of them out there.
Larue felt that there was enough of an issue with the original chamber that he changed to the XTRAXN chamber.....either way, both iterations are proven shooters.
I have a few rifles with fluted chambers HK 91, HK SR9TC and several SVT 40's which all leave flute marks on the brass. But I have never had any trouble reloading the brass. Other than some carbon marks may remain even after prolonged after cleaning.