Just wanna throw my 2 cents in:
The Sennheiser HD5__ series is great for gaming (spent a few days with my friend's HD598) but I personally felt the sub-bass was rolled off, and that made for a very incomplete listening experience for metal. I really disliked them for music, but they were fantastic for gaming.
A closed back option you may consider is the Meze 99 Classics. I've had them for the last few days and I can say that they are by far the best headphone I have heard to date. The soundstage is surprisingly large for a closed back headphone, and the sound signature is very fun. Good bass, with a slight emphasis on mid-bass but good extension down low as well, and great mids and highs as well. Truthfully I am having a really tough time finding fault with their sound signature. haven't tried them for gaming quite yet, but I will soon, and I have no doubt they will be great for it.
They may be about $10 over your budget though (depending on where you are), so you may have to find them used.
Ahh....... there was a second page. Sorry, didn't realize you had already made your decision. Hope you enjoy the Fidelio. I almost bought them, but I needed closed back so I went with the Meze.