I do not have the MK6, I have a Hollis PRISM2 that I am just beginning to learn to use. My instructor is an instructor trainer on the MK6 through SSI & an instructor at various levels on the Hollis through TDI (Air diluent, Trimix diluent & CCR Cave). Having taken Professional courses & technical courses through this instructor, I can guarantee that he is about the most thorough instructor I have EVER seen, regardless of the unit. He has had me reading all kinds of manuals & accident analysis reports & such, plus I have already gotten over 12 hrs pool time in. I just got the unit into the open water for the first time last week. The units are fascinating for sure,... I just decided on the Hollis because of my technical diving interests.