I just received my newest housing, a Seacam for a Canon 1DsMKIII (21 megapixel). Wonderful housing, although I totally expected that having migrated from a series of Seacam housings previously including 1DsMKII, 1Ds, Nikon D1X, Nikon F100, and Nikon N90. However, with the new housings I got dual S6 bulkeads. See http://www.seacamusa.com/s6-connector.shtml for reasons why I think S6 is so very superior to standard Nikonos V connectors on a housing.
Having spent the past 2 weeks shooting the new housing I'll confirm the S6 is a joy to use. I'll never go back to N5, and would hope one day all housing and strobe manufacturers will see the (strobe) light.