you have all the elements for a stunning fly. Your wingset is killer and the black tippet line matches with the herl so thats bonus points! With very small adjustments this would be an 11/10. A shorter, steeper tail crest would be the main adjustment I would make. I would suggest finer oval tinsel for the tip but the same number of wraps. I would also suggest one less rib wrap. Not because 5 is the standard number but it would look better in this case IMO. I would also be very selective about the body hackle I chose to try to achieve a better hackle taper and select a throat lenght to extend that taper through the throat if possible. Keep in mind I am a fly tying hack and these opinions very well may be different than your own and others. Marty also tends to tie a longer tag than most and while thats not my style I think it would look killer on this fly.
I normally wouldnt be that nit picky because my flies arent nearly this good but you were very close to absolutely knocking it out of the park.