All that said, a traveler will certainly prefer the SE310 construction as the noise isolating is far superior on the SE series. I think though that this is primarily due to the black soft conical sleeves. Love them!
If you can swing it the SE series has impressed me mightily, but bear in mind that my own personal filter is largely tied to the construction in combinatioon with the sound. The sound issue alone will require sample music and a bit of time with the product, pre-purchase.
Mike
You had mentioned something that I wish I could find: a store with a good selection of headphones that you can compare and try out BEFORE buying them. The only 'try before you buy' display I have seen was at a Best Buy with the ability of listening to a couple of different Bose TriPort over-the-ear models.