Hi Jon,
I am currently diving the configuration you are referring to (A1 with Ikelite housing, Inon100 and dome).
While I like the additional angle the 100 and dome offers, I'm not happy with the loss of detail around the edges. Zooming slightly improves the image but doesn't completely eliminate the softness and the resultant reduction in WA is not an acceptable trade-off in my opinion.
I think the only solution is to pay for good WA glass - unfortunately not an option with the Ikelite housing. There was some discussion previously about Ikelite manufacturing a port that would accept the Sony 0737Y WA converter but that didn't materialize into a port being made commercially available. For topside use I have found that converter to be quite acceptable.
Amphibico is developing a WA solution for the CMOS Sony's that should be available late summer for about $2K. My original thinking was to purchase the EVO Pro housing and their new lens when available later in the year. The new EVO (ELITE), however, has the rear monitor - which I can work around - but DOES NOT have access to full manual focus, exposure or telemacro. The original EVO Pro SE, which had all of those features, is no longer manufactured and although listed on a few reputable camera websites is not actually available (sites not updated - only the ELITE being carried).
To make matters worse, it appears that Gates is no longer making their A1 housing either and the used market for both housing appears to be dry.
I have been very happy with the A1 for my purposes. It has been involved in providing footage in multimedia projects for the past 18 months and has accompanied me to Africa, the North Atlantic, Carribean and places in between. The image quality (in the right environment) and the portability are exceptional.
Without a good WA solution and housing to match, however, I am starting to consider alternatives.
Alan