Like title said this is a huge problem now, there are a lot of people with Vermilion wings and it causes high FPS loss.
We tested it yesterday during weekly raids and my team experience FPS loss from 10 to 30 frames, for some of them raids become just slide show and I had to turn off my back skin (and swap to other class cause I don't want to play on class without complete glamour ). After that everything back to norm. We tested it on Chrono and FB and problem not class related but skin related.
This problem affects not only raids but all open world areas and WvW, now everyone uses this skin and FPS drops in open world and WvW become unacceptable, even on high performance PC.
We have two back items which causes huge FPS drops in a short period which result in general performance degradation.
I think here we have 2 possible solutions:
1) Some king of optimization (but I doubt that this is possible or easy to implement in short time)
2) Add options to disable player auras\effects\back-items-skins like it done to armor and weapon glamour (this option will be the best in my opinion as it will help most number of people either in open world or WvW, there are a lot of other items which cause FPS drops and can't be disabled or hided)
I hope this can be fixed ASAP because it becoming more and more critical.