In all fairness you're comparing IEMs to a pair of full sized cans. From my experience with the Shure line (e2c, e3c, e5c, e500), I can say that the E5cs and E500s (more so) are very good performers, in their category as far as detail and bass extension. What I didn't like about IEMs, in general, is their lack of soundstage\space. No matter what IEMs I used in combo with a number of amps, I kept feeling like the music was trapped either inside my head or just outside my ears, 2D effect! Which is why I abandoned them. With the HD650s, along with a majority of other fullsized cans, I noticed an INCREASE in soundstage and more 3D imaging, better instrument separation. To me,it wasn't worth the 400 (I bought the e500s a ways back) price tag in comparison to headphones of the same price. You're paying more for the miniature architecture.
Either way, it might behoove you to try both and send the loser back (I know it's bad practice,but without being able to demo at meet,....), both can be found online with good return policies. Or better yet (for the retailer), put the loser up for sale in the FS forum, they're both still in demand, somewhat.