OK, so this is an old thread, but I just got involved. Anyone still listening? 
I just sent a few pictures to our Alaska State Fair of which I am pleased to say that I got Honorable Mention on a PhotoShop'd piece I literally spent days on and am still not finished.
Anyway, I went through all the Dry Creek setups and to keep this simple, I sent in a full gamut shot and again the same shot with a reduced gamut that supposedly fell within the range of COSTCO's Noritsu printer according to PS. The full gamut was nicely saturated but the reduced gamut was weak - just as on the screen. I'm not sure I get it. I expected the reduced gamut to be about right and the full gamut entry to either be dripping ink off the page or a black mass of color goo. There must be a 1-1 correlation between PS Gamut Warning and the actual capability of the printer for the shots be as on screen. I think in the future I will not worry about the gamut warning.
Anyone else experienced with this?