I've not used them but speaking anecdotally, when I asked my local LGS owner, who I do trust, about these sights, he was well less than enthusiastic.
Take that "review" for what it's worth...which obviously isn't much. Just wanted to throw it out there.
I'm sure others like them just fine. I'm partial to Troy, or they would likely have a place in my safe as I do like (and own) other Magpul products.