The Beyer DT-250 looks very good, I may just give that one a try...
Also closed back etc, probably very comfy.
I noticed that its freqs are 10 - 30,000 Hz too.
Where as the sennheisers go 8 - 25,000 Hz.
But I guess it's all in how those frequencies are tweaked up/down, no?
What turns me off though is that the Beyers only isolate 16 dB, where as the Sennheisers do 32 dB (which kicks ass, because I'm often in a pretty high-noise environment).