Get these then!
http://img56.imageshack.us/img56/9703/406088jpg.jpg[/]
What do you mean closed aren't a proper pair? If anything closed are a proper pair as they are used for monitoring sound, what i use mine for. I personally favoured the closed DT770 Pro's over the DT990 Pro's, just had a much cleaner and punchier bass frequency response.
I bet you those Beyers will withstand a lot more than the Sennheisers anyday! :p (Coming from personal and professionals experiences)[/QUOTE]
For studio/monitoring yeah but for actual musical listening open-air provides the most neutral, open and natural sound colour.
Closed back cans just sound too confined to me and I have some decent equipment to drive them :p I've had many and Grado Open air too but the comfort on Grado cans leaves many questions.....Sennheiser all the way.
[img]http://robbiekhan.co.uk/photos/nav_portraits/IMG_5010.jpg