This has been a pretty intriguing caliber that was the brain child of Dave Tubbs in conjunction with Hornady. It was designed for long range shooting and had a fair amount of hype built around it, but unfortunately few manufacturers jumped on the bandwagon initially. Ruger and DPMS were some of the first manufacturers to build a rifle for the caliber, but luckily Savage Arms jumped on the bandwagon not long ago.
Criticisms of the caliber are that performance isn't as good as the 6.5x284 Norma, and that it is a barrel burner (but so is the Norma, so that's a silly argument if you ask me). Brass availability has also been a big deterant for many.
The 6.5x47 Lapua as mentioned by jefo65 seems to be a superior cartridge by most reviews due to case design to capacity. Supposedly it promotes a more efficient powder burn, and has a longer barrel life. Although you will likely have to special order brass and ammo, this would get my vote (plus its less common, so I like that)
If you do end up buying one, I'd be very interested to hear your thoughts as most gun reviewers create a bias quickly and most readers just parrot what they read.
Take Luck!