Thanks for the above comments, I really do appreciate the input, especially from people who have used the various phones. And the comparisons are very helpful. Singing to the choir, I wish there was a "headphone bar" nearby, to stop by and try/compare the various phones ...
I remember trying the E4s out just to see what they were like shortly after they had come out, when I purchased ny first set of IEMs, a pair of Shure E2Cs. I liked them, but couldn't see justifying the then high price, in the face of the E2Cs. And as I said, it's only the current price-point that brought them back in mind.
I really don't need another pair of phones--I actually have been content with my Shure SE210s, a gift (I know, it's heresy--or complacent ears). But maybe it's a bit of nostalgia ... I'm still using my Sony on-ear phones (with genuine leather headband, no less) from 25 years ago, and love 'em.
(And agreed as to those damned plastic clamshells, which I in fact have gashed myself on. Wonder when someone will be bringing a lawsuit.)