^^I wanted to wait for more listening time before posting more impressions about the HJE900, but i have to comment after this question :
Foam-modded HJE900 with around 90 hours of burn-in sounds EXTREMELY similar to foam-modded hippo VBs with several hundreds hours of burn-in...
Pretty much the exact same mids and treble presentation (energy, positioning, and coloration-wise : same warm mids and brightish extended treble at the same distance from the listener), but HJE900 has very substancially more midbass and less sub-bass than VBs, bass also feels rolled off compared to VBs as it doesnt extend as low.
This lack of midbass hump and better bass extension might contribute to the fact that VBs soundstage also feels more spacious and 3-dimensional.
Besides better build quality, comfort, look and ergonomics (which count a lot), HJE900 do not feel like an upgrade AT ALL over hippo VBs so far (2 days of listening). And SQ-wise, they also dont feel like an upgrade over a painfully deeply inserted pr1pro to my ears.
I like (sometimes love) both VBs and HJE for acoustic instrumental music, although i far prefer the more linear bass presentation of the VBs (mostly boosted at the lower end only), which better 3D soundstage effect also is noticeable with some recordings. After HJE and eterna I can now affirm that I personally officially don't care for those distracting and music-altering midbass humps!
With vocals, it depends a lot on the recording. Both present them pretty much the exact same way (with foam mod). Vocals often feel just a little too laid-back in the mix, and sometimes lacking weight in the lower mids. Also both will equally highlight any preexisiting vocal sibilance in the recording, which can be painfully distracting at times, but again this is totally recording (and rip) dependent.
But sometimes vocals can also feel beautifully lush and warm......