I know that Scott Sanchez, the Convertible's originator, tied it with the One Fly competition in mind and would do field mods depending on the situation, fishing it as anything from a dry to a spinner to a streamer (the original had a marabou tail). For me, they've been a bit of a chore to tie, especially getting the calftail Trude/Wulff wing right; I always just fish them intact.