Interesting, clever design. A little on the complex side.....I wonder how subject to failure that "grabber" thingie is.
I haven't checked out the price but it sounds as if it might be more than is in my wallet. 
i would think its dependability would be as good as any extractor. of course with design being dependant on two extractors, it would be twice as likely to fail.
IIRC, by having a straight feed, the chamber can be just a little bit tighter, reducing the gas loss at the breech. Probably a pretty minor effect, but Arne tried to maximize velocity out of this package, and every little bit helps.
There's an animation of the action here: http://www.bobergarms.com/video/boberg-xr9-patentpending-feed-1
thanks for the link!
