Not everyone like this fly. Actually I guess most people hate the design. I don’t know what I do, but it catches me some fish every now and then.
Often it’s stated that the parasol creates a propelling effect and mess up the leader. That can be true if the parasol is to long. But if you hold your horses and doesn’t exceed an inch (2,5 centimeter) in length you’ll do fine. Also make sure the parasol is stiff – I like to use tippet material in 3X for hook sizes round 16-18.
The fly actually looks more difficult to tie than it really is. It is also easy to fish. Just like the old days when you fished with worms attached to a floating cork.