Thanks to a helpful fellow head-fier, I managed to get a pair of vt-h68. Like it was previously speculated, it does seem that exibel mhx10 and vt-h68 share the same driver. I did not remove the drivers from the housing, but back of the drivers looks identical. Interestingly the headphones sound very different.
Mhx10 is a lot darker, vt-h68 have overall better balance between lows, mids and highs. Actually tonality of vt-h68 is allmost identical to what I wen't for when I eq'd exibels. Unfortunately for vt-h68 the more natural tonal balance is the only thing they are better than exibels.
Soundstage is clearly bigger on exibels. And it's not just that DS headphones have not so impressive soundstage, those completely fail in taking the music out there, instead of sounding like two speakers next to my ear. I listen to a lot of stuff with drastic stereo separation (hendrix, beatles etc) and DS is not good for that kind of music at all. When singer is on the left, and guitar on the right the end result with DS is quite bad. Exibels create more speakerlike sound field. DS sound what you would expect from a $20 on-ear headphone.
DS have a metal plate inside the earcups. That helps in creating more clarity to the sound. I've added metal to the cups with many headphones I've modded so I know exactly how it affects the sound. Even though it helps in bringing out the highs and overall clarity, it leaves an unwanted track. With closer listen, the sound is not natural. There is a metallic sounding backwave which is more obvious with certain songs than others. Highs get a bit splashy, upper mids get sharp...and sometimes you can even hear a faint echo.
Even though Exibels have major problems with excessive bass, the timbre on midrange and highs(even how recessed those are) is close to perfect. DS sounds like an unfinished prototype in comparison.
If I were to sum it up, I'd say that exibels are a bass heavy headphone with quite muddy sound but underneath there is a world class headphone which needs to be digged up. DS on the other hand sounds more impressive out of the box but with closer listen emphasized stereo separation, lack of soundstage and metallic nyances in sound make it bit mediocre in the long run.
Talking about build quality... People who have been impressed by the build quality of VT-h68 should really check out the exibels if possible. It is no contest. Cushioning on the earpads of DS is some traditional fluffy foam, Exibels have memory foam. Pleather on exibels is really nice, on VT-h68 material more like a thin layer of fabric appearing like pleather. Exibels have nice stitching on the pads, something you see on more expensive headphones. DS pads are like 30cent pads you can buy from aliexpress.
Earcups on DS are indeed metal, those feel bit plasticky but those are a real thing. Exibels cups are plastic with rubberish coating. Really nice, but I give DS an edge here.
Cable on DS is really basic, nothing special and the way it connects to the headphones feels a bit cheap. Exibels have a nice cloth covered cable, metal cover on buttons and next to connectors and connecting the headphones to the cups gives that satifying click
Hinges are nice on both. Metal... But Exibel hinges are more polished and have stepped system on adjusting the headband. Stepped system with numbered settings it is a lot easier to adjust the headband on exibels than it is on DS.
How you like the design is a matter of opinion but better built with parrot zik look a like design makes Exibel a lot more pleasing to the eye Imo.
All in all I feel that Exibels are clearly the flagship model, despite the lover model number- VT-h63 vs h68. DS are a nice headphone for the price. Not more though. You can't really eq away the metal resonances, but you can eq extra bass of exibels. That + clear differences in build quality + same price = Exibels are better of the two, it's not even a close call.