Lou,

I've compared the ZAO-II and BCO to the Delos.

The 6mm ZAO-II versus 6mm Delos is here. It is repeatable over several nights.

I compared the 10mm BCO to the 10mm Delos along with my 10mm ZAO-II only once and found that the BCO slots in between the ZAO and Delos. I have not repeated it yet as I hadn't gotten a chance since.

Hope that helps.