Cookie, I posted about this on AR15.com. What you saw was NOT the Knights lower.
This is what you saw:
http://www.ar47.com/
I took a few pictures of it when I went to the creek. Here are a couple that I took:
and
If you look at the pic above, you will see you have to make a milling cut to the underside of the bolt carrier.
You also need to mill a little off of the upper receiver to clear where the mag goes in on each side.
The Knights version is going to be mucho bucks and it will NOT be compatible with existing uppers. The upper and lower are longer than regular AR/M16 upper/lowers.
It probably will not take a RDIAS while the one that was at the creek will.