I haven't tried the E40's, but I've tried the SE215's. My lord, the fit and sound isolation alone were almost enough for me to buy them. It's incredibly snug although a little cumbersome to put on because I wasn't used to it yet. They're quite bass heavy and in general, it's very muddy. This muddiness stopped me from buying it.
I agree with phoenixsong with the Philips Fidelio S2 recommendation. I felt there was a good balance of everything with them and I loooved them however one earbud stopped working after a few months.