It really depends on what you are going to do with it. If its a sporting gun to go win matches at 600+ yards then go with the 6.5-284, the ballistics are far better than a .308 at range; but it comes with serious availability problems for components. But set-up correctly it is a fantastic shooting round. Just make sure you have a 1000 yard range around otherwise its dumb.
If you want a general purpose gun that you can also take to matches then get the .308 for all the reasons everyone mentioned above. You aren't going to take your 6.5 hunting.![]()