have not used them but those that I have talked to that shoot in F class to 900m (Calgary, AB) have found them to be really good. They claim that the optics are up there with the best European grades and the adjustments are second to none. Metal to metal throughout. If they are as good as they claim, they would be much cheaper then Nightforce and in some cases cheaper then Leupold. Also, the reticle styles are a lot more useful then mildots.
If you can look through one and try it that will be the only way to know for sure. Check out cactustactical.com for more info.