Sennheiser HD 25-1 II vs Beyerdynamic DT 770 Pro

After having used the iPod earphones for countless of years I found it was time to finally switch to a decent pair of headphones. I've narrowed it down to the Sennheiser HD 25-1 II and the Beyerdynamic DT 770 Pro. From what I've read here, the HD 25 is pretty popular, and most people are satisfied with them. Same thing goes for the DT 770, but they are not as well-known as the Sennheiser. They cost about the same, so that's not an issue.

Isolation (music coming out of the headphones, but more importantly, "not a single sound" coming into the headphones) is a very big thing for me since I have a pretty long commute to school. Sound quality as in highs, lows, bass,.. doesn't really matter to me since I listen to all sorts of music. Besides that, they should be easy to handle, so I can carry them around wherever I go. I've also picked up that the DT 770 has some issues with portable devices, like an iPhone 4, because of the 250 ohm. I'm pretty reluctant to buy a DAC/AMP to fix that, since that would easily increase the amount of money I'll have to spend to get a decent portable setup.

I can't really make up my mind. I'm hoping for someone who owned both headphones and could tell me some things he/she liked (didn't like) about them. Similar headphones within the same price range are also welcome. 

On a sidenote: I'm also looking for some advice on cheap (20-40 EUR) IEM's with decent sound quality, which I can use for running etc (not worth starting a new topic over).

So the HD 25's will do just fine, even without a DAC/AMP? Are velour pads a must btw? I don't want to lose too much isolation.. 

Could you give an example of how good the isolation really is? Did you ever use your HD 25's during a loud trip or something like that...?

K_19 sure made the HD 25 sound awesome :p.

Any other Head-Fi'ers who do use a DT 770 when they're on the go and care to give their opinion?

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