I have the jh16fp and have demo'd the ue18 several times
Both are nice, the ue18 is a bit dark sounding while the jh16fp's lower mids are a bit over thick ("honky" people say). Neither will have the midrange richness of the 846, the tuning is different.
I would look closely at the Noble K10, these are warm in the mids, but with better treble extension than the 846, to my ears (I've spent a little time with the 846 and own the k10)
You can also get a custom-fit sleeve for...