Just an update, I received my A700's today. They are quite a bit different than the Bose "Around Ear" headphones (previously called Bose Triports) I'm used to. I was actually ready to return my A700's at first, but after listening closely, I'm able to really understand what people are talking...

So after alot of consideration, I think I've decided on the A700s. This is mainly because I've decided I need closed headphones for the added bass response and noise cancelation. The biggest turnoff of the HD555s is the fact that you need an adapter to use a standard 1/4" headphone plug...

I know there are multiple other threads debating these two headphones, but the current Sennheiser rebate is making things difficult for me. I'm primarily interested in using these headphones for gaming and music. Mainly important to me is the ability to determine where people are in games...