If you read Barsness's 6.5 Credmoor article in the June, 2011 edition of Handloader, you'll discover it's designed to avoid some of the design faults of the .260 Remington. Much like the 6.5X47 Lapua, but with a bit more case capacity. That, and the fact that they come in a cheap factory rifle that has outstanding accuracy with factory ammo. Alot there to like.
If you play with long range shooting much, two things become apparent. Wind is usually your biggest problem and, to deal with that, you need lots of practice. That tends to require a light(er) kicking rifle that doesn't eat barrels much. One of the major reasons why the .308 is still very popular for this.
So, I for one, think they are a great choice. I seriously doubt I'd try killing any game past 400 yds. with one, but that's because I have little confidence in my ability to make a wind call more than anything. Non game, like coyotes, and ground squirrels however would be a different story. E