I had Protone, Proddysey, Minimax, B2003 before I bought the Noah. (Not really a good investment plan, buying them twice, but unless I had time to really check out these plugins and find out how good they all are, I probably wouldn't have bought the Noah.) I find myself wondering if there isn't a tiny bit better sound coming from the Noah as well. Not *that* much of a difference, but the sounds just seem bigger or something. Pads from the Proodyssey sound richer.
I build multipatches from scratch, not using any pre-configured effects . I'm going SPDIF into a 3216ddx mixer, and from there to the Creamware card, so there's no AD/DA conversion to add a new factor to the sound. I doubt that the digital conversions along the way would affect the sound, but I can't say I know for sure (but I do know it introduces measurable though often insignificant latency

) What is your signal path from the Noah to your external amplifier compared to the Creamware card's ? (Obviously, if you're going ADAT from the Noah into the Creamware card, the signal path will be the same).
Anyways, whether it's better or just my imagination, or postdecisional dissonance reduction, Noah rules! It's a lot of fun to play live (and takes the strain off your Creamware card).