I didn't get either in the end, i had to have a bit of work done on the super V, some of which included getting the rear shock custom valved. The new rear swingarm turned out to be significantly better than the previuos one, a custom valved shock improved the ride tremendously aswell. I since ridden more Geminni's and Bullit's, and i think its more down to personall choice and which brand you want to buy into. I would probably go for the Gemini, I rode a downhill specced version and it felt as solid as the similar specced Bullit, and i always liked 'Dales. To chuck a bit more confusion in to the mix, i ridden a number of Prophets, which impressed aswell.
I think the Gemini is the one I want. Like your posts I think I have already made up my mind. Was just worried is wasn't quite hefty enough for the stuff i think I want to try. But then the whole reason I like it is because it is light and flickable. Was the gemini you rode a proper Dh replica or just a 2000 - 900 gemini specced for downhill?
I rode just every cannondale model for 2005 and a few custom Gemini's too. One was very DH orientated, Boxxer's, single ring, etc. It didn't feel all that good untill the trail started going down, then it came into its own and the set up made a lot more sense. It still retained an element of "chuckability" that i liked about the stadard setup aswell, which was cool. I couldn't comment on the durability of it obviously, but i'm around 15 1/2 stone (not from pie-eating either) and it felt solid without being over the top.