The one in your link does both the angle and the cosign. I like the idea because it saves $$ over any other set up out there. The NF set up that Shawn makes is around $250. If you just buy the aci oracd he uses and the level as a separtae set up (which I also have) it puts you right at $200. As long as this thing isn't a piece of crap, to me, it's a no brainer.
The little black aci I have the comes from badger and other places isn't as "tuff" of a unit as I thought it would be.
The Horus Vision unit gives you both the angle and the cosign which is good for me since one method allows for quick math if you need it and the other is what's required in LB3 which is the software I use. I believe you can use angle or cosign if your using exbal.
