Thank you for your reply.
I don't think listening for relatively brief sessions would be an issue, either. However, I tend to get really wrapped up in the music and often listen for far longer than I intended. :)
I have a pair of igrado's on order. These can supposedly be modified (by removing an internal foam cover) so that they sound similar, if not identical to, the 60i's. The umodded igrado's are supposed to be a bit darker and have more bass than the 60i's unmodded, so I guess I could "unmod the mod" and return to it's original sound signature if I so desired, at least theoretically (I don't have the igrado's yet so have no idea how they are constructed).
Please post your thoughts in the iGrados when you get 'em. I am really looking for a replacement work headphone, and I am thinking of going back to IEMs. I have read reviews for the GR10 IEMs on Head-fi, but $400 is a little crazy for me. I am not expecting magic for the price, but I am curious to read what you think of these.