John,
indeed it is a bold claim. Terry Griffiths (Photographer fly tier and writer) wrote in Fly Fishing and Fly Tying that "The CdC and Elk is the best dry fly for both river and still water he has ever used." I can swallow that a lot easier as he is saying it about someone else's design (Our very own Hans W.) To say it of your own fly is... well going too far.
On its day that fly is good, it hasn't caused me to kick any other caddis pattern out of my box though. I do like to be able to pull it under and have it pop up. That is the main reason I use it.
Lastchance, you could but it is a caddis imitation. A friend of mine shot film of caddis emerging under a microscope. That film convinced us both that here is no point trying to imitate an emerging caddis at the surface. They emerge from pupa to adult in well under 1 second. The fact that many fish are caught on flies that supposedly represent emerging caddis just proves the furthest our reasoning can go is that a fish eats a fly because it can. I'm not sure o what caddis emergers are taken for, but its doubtful they are taken as caddis flies emerging when they are not available for long.
Cheers,
C.