I have an X Bolt in 7MM-08....stainless stalker. The rotary magazine works great. The only hiccup occurs when I don't fully retract the bolt to the rear. If I don't fully retract the bolt, it will not feed another round into the chamber. The lenght of the Standard Short magazine is longer than that of the A Bolt, so handloaders will like it. A good friend of mine has a Mountain Ti A Bolt, and we compared the two, mine is longer. I don't forsee you having a problem accidentaly releasing the magazine, but make sure that it is full seated or you will have problems feeding a round. Accuracy out of mine is less than MOA and I couldn't be happier. I shoot the Hornady Superformance 139gr SST's and they perform flawlessly. On a scale of 1-10 considering other rifles and prices, I would give it an 8.5. The only flaw I could find, was rust starting to form on my bolt after a week out in the elements chasing high country mulies.
As far as 308 vs 7mm-08 well we could argue that forever. BC's are better for the heavier bullets commercially available for the 308, but if you aren't a comp shooter and want a great deer round you can't really beat the 7mm-08. My buddy loads 160gr Bergers for his, so if you reload, then bullet selection won't be a problem. My gun didn't shoot any ammo under an inch other than the Hornady Superformance. I put two types of Federals, two types of Winchesters, and Remingtons through it. I liked the power of my friends 160gr handloads, but my rifle was sighted in for the 139gr SST's and I wasn't messing with it the day before the opener.
Buy the gun and you won't be dissapointed.