I use ground turkey on and off, but I've decided I don't like it as well as I thought I did. I think maybe it's the color. It kind of turns me off while cooking it to see that almost white meat. I guess I would feel the same about ground chicken. I do agree that cooked in recipes, there's not really a discernible difference.
I did notice, however, that the fat content is actually less in the lowest-fat ground beef. Of course, that stuff is expensive.