I bought one this winter. I did not put a brake on it. My main use is target, so I mounted it in a choate ultimate sniper stock, filled the extra spaces in the stock with lead shot,(rifle weighs in at about 21lbs....shoots like a pussycat), topped it with a leupold 6.5-20 50mm long range target scope. my last set of groups I shot (have not worked up loads yet, just picked one load) were 3/4" and 1 3/4" at 400 yards with a cross wind and alot of mirage.
I made a set of should straps for it so I carry it like a back pack rather than on 1 shoulder. BIG difference. went coyote hunting
this winter on snow shoes. carried it over 2 miles...very comfy. (no coyotes though). I am currently shooting 190gr Sierra Match kings.
I absolutely love this rig. I had initially considered the 338rum version. I just find the 300 to be more economical and it does what I want it to do.
but...can't tell you how it shoots with the original stock...never tried it. I have considered putting a brake on it but I am afraid to mess up the accuracy. maybe someday.