Little bit shorter than 300WSM, this was so it would fit the remington model 7 and similar short actions so remington could use existing actions without having to do modifications. Sounds like it is 100-150 feet per second faster than the 30-06. If you get one, you are probably going to want to reload for it. Factory ammo might get pretty hard to find. I kicked around the idea of picking one up (fair deal), but in the end it doens't give me enough over my 30-06's to get excited about.
Rumor has it, it is inherently more accurate than the 300WSM (this was per benchrest shooters comparing the two in multiple rifles). If none of the downsides listed turn you away then go for it. I'm sure someone will chime in with first hand expirience, as I know a few member use them.