Wade,,, like you said it does actually depend a great deal on what kind of water the carp are living in. The carp that I smoked were taken from a small river near my home that has very clear, constantly running water. I do a lot of trout fishing there but during the carp spawn these huge breeders come upstream and are fairly easy to arrow. They are so large they look like torpedoes

The 2 fish that I smoked were about 20 pounds apiece. I scaled them, filleted them leaving the skin on and smoked them as usual. I still remember the appearance of the meat after cleaning them, it was very firm and had a very dark red color to it. It smoked up beautifully. But like you said,,, I guess the ones that come from that mirky, dirty water environment taste different, which makes sense...
Jeff