I'll give you my differences which may differ from others but Don Douple was my mentor and taught me how to tie and fish them, so you decide. (Edit: Now tying this fly is simply wrapping chenille around a hook so how much did he need to teach me? Well when Don taught me curved hooks were not really on the market yet so he taught me how to bend the hooks to the proper shape.)
Three things differ and my added point.
First is the material which is hard to find but definitely important although may not be as important as 2 and 3 below. It is cotton chenille dyed Neon green. Don's theory is that the cotton feels more natural when the fish bite it and they "may" hold it a faction of a second longer.
Second, it should always be tied on a bent hook like a Tiemco 2457 in size 6.
Lastly, there is no tail.
Now my added point is never to weight the fly and only fish it with shot about 16 to 18 inches above the fly. I think weight takes away from the action of the fly which, in my opinion, needs to spin freely in the water. Now I base this on personal experience where I was fishing the same run with another guy who tried to improve the fly by using tungstun wire wrapped under the material. I hooked maybe 10 fish (give or take) in the run and he hooked 1. He switched to one without the tungstun and immediately started to hook fish. We are both capable nymph fisherman and the only difference was his added weight.
For what it's worth.
Also, like any fly confidence is key. I know the fly works and I'll fish it longer without switching because I know it's only a matter of time. This is true with any fly you've caught fish on not just the Inchworm or as Don now calls it, the "greenie worm". I know guys that excel with the traditional Green Weenie tied with weight and tails, so don't under estimate confidence in a fly pattern.
