I saw one of these rifles in the gun shop today for the first time and I was intrigued. A light compact rifle in .40 caliber that folds in half on a hinge (barrel folds up over the receiver and stock and locks in) and uses Glock magazines. I've got a carbine rifle in a same handgun caliber as some of my handguns, so I appreciate the versatility and modularity (is that a word?). Lots of potential for custumization. If you have a Glock pistol in .40 with plenty of mags (including some high cap mags), I could see a lot of advantages to having a folding light compact rifle that not only uses the same ammo, but the exact same mags. That would be great for camping, home defense, etc. Perhaps these are old news, but it was the first one I've seen.
I don't have a Glock, so it's not something I'd buy at this point, but it was a really cool concept and execution. I don't know how they shoot or anything like that, but if anyone has one I'd be interested to know how you like it.