ES10 should be more expensive to acquire but not by much, I happen to have one. It's one of the best portables in the market right now.
It's definitely not similar to the HD650 at all having a V-shaped sound signature which means big boomy basshead levels of bass and prominent treble. Mids take a backseat but not by much. They are still prominent and very energetic in presentation.
These have 70mm drivers (I believe) which are larger than what your normal portable can has, they are comfortable to the head as well and all I can say about the sound is that these are "big"
Can't go wrong with these cans, they are very good portables but they are definitely not like the HD650 at all