Jeff, I have a few Coopers, Sakos and a Kimber and they are all great rifles in their own way. The Coopers have a 1/2 moa guarantee while the Sako's offer 1 moa and the Kimber, well they dont offer anything other than saying the use match grade barrels,triggers and are bedded. In my case, they all work great for their intended purposes.
Since you mentioned the 6.5x284 that Cooper makes I post a pic of my M22. It likes a diet of R22 and 142 SMK's.