Bonus though with the 2 output lnbf, it can see both H and V channels.
Wouldn't a single LNB also see both H&V polarities? Now I'm confused!
Sure, but only for the "master" receiver. The slave receiver could only see whatever polarity that the master is tuned to at the time, either H or V. A dual output lnb though, is like having TWO complete single lnbs up there, and each one is separately controlled by the receiver it's hooked to.