The DuoStock has been around for a bit, but I haven't seen a whole lot about it on the nets. My buddies at BreachBangClear got one my way as they use and recommended it. From what I hear, people tend to love or hate this thing. I tried my best to be neutral, but I did see examples where people didn't want to try it based on looks alone. I will have to say it does look a bit dated and could use some more rounded edges. In the end however, it functions as advertised. Although it has the basic features most stocks have such as adjustable length and sling attachment points, the big design spotlight is the curved end.
This allows the user to easily go from a low ready / patrol position to a firing position in one smooth motion. When used this way, it also places the weapon up higher than traditional stocks so the user does not have to raise shoulders or lower their head nearly as much. A big thing I think some people who don't try the DuoStock miss, is that there is still a good chunk of traditional near-flat space on the stock. This allows the user to choose whichever platform is best for the situation which can certainly vary between whether armor is worn and shooting positions. The feel of the cheek weld isn't quite as nice as some of the fancy modular stocks, but gets the job done. Currently only available in Black, but made in the good ol' USA offered in MIL-Spec and universal sizes for the AR-15 platform. For those who feel pretty "meh" based just on looks, I highly recommend giving the DuoStock a try first. The design could be modernized, but I feel the functionality has real merit rather than just being a gimmick.
Recommended place of purchase: