I just had to share this. I have a lot of headphones/canalphones. I have been trying to explain to my roommate for years what the draw was for me to the canal phones.
I just let her try my ER 4Ps to show her that they can be comfortable. Then I let her try out the E5s. She found them equally comfortable (I don't).
The funny thing was that she said to me - "is it my imagination or do they sound different?" It was just funny to me that someone who knows absolutely nothing about headphones and is perfectly happy listening to the crappy sport type that came with my Creative Zen could really hear a difference between the Etys and the Shures.
Neither one of us could really explain what the difference in the sound is (unlike others here) but we could both hear the distinct difference between the two.
L.

(The song playing on the iHP was Josh Groban - Per Te, if that makes a difference to anyone.)

do either of you prefer the sound of one over the other though?

We both prefered the Shure.
I'm biases by the comfort I find with the Shure. She just liked the sound better - I asked and she can't really define why, but that is the one she picked (without my input )

good song... GREAT album!