I prefer Bartlein first because I like their 5R barrels but now that Kreiger makes them too that's a toss up , I'd say Obermayer but they're such a hard find I don't even look for them anymore
I have had rifles barreled with Brux , Bartlein , Rock Creek , Obermayer, Kreiger , Pac-Nor , Hart and Douglas and all have shot fantastic for me.
In the end I think it boils down to how well its installed. I've seen a standard Douglas barreled rifle built by a perfectionist on a Savage action out shoot a Kreiger barreled Bat action because the sausage that fitted the barrel up was half retarded.
I don't think you can go wrong with any of the bigger names so ling as the barrel is fitted properly