Yeah, all of them really do dip in the lower treble unfortunately. If you can, audition the UE 900 as the dip is between the 4.Ai and 4R, so I don't know if you'll like them. They actually do have strong extension on both ends though and the sharpness that an Ety would have (but not the lushness ). FitEars should fit you nicely actually looking at the treble region's graph. The Heir Audio does have a big dip at the 4k, mine measure like that as well; I'm assuming its part of the sound.
My suggestion is to look into something that is neutral for what you like.