I've just replied to Nik in a PM, but guess i can put my impressions here:
Based on very very very early listening of Utopia:
The utopia is an awesome headphone, and very similar to the Abyss IMO for what it does.
Comparing the HEK to the Utopia/Abyss are very different, so easy to form an opinion there as they are different ends of the spectrum.
But what i love about the abyss is the amazing power, authority, clarity. The utopia does all of that really well also, just different.
One user said it best, the abyss and utopia are like different flavors of icecream. Depends on your taste. They are very much different, yet still very similar lol.
The Utopia has a more full bodied lush sound. And handles mids/vocals etc more naturally so better to my ears. The abyss in contrast can be considered too analytical / harsh when compared to utopia for vocals/mids/highs. Where the abyss really shines is in the bass. it's so powerful, so forceful. The utopias have awesome bass as well. But id give the edge to Abyss there. My issue with the abyss is, depending on the track and fit, the bass can loose control, and i may have to re-adjust the headphone on head to solve it. The utopias on the other hand are a normal headphone fit. So it will sound consistent every time with no adjustment required.
The abyss has the ability to sound open, spacious and wide whiles still sounding forceful, accurate, immediate, aggressive. The utopias are very fast as well, but does that in more of a way that a closed back headphone would. So it does not have an open sound. It really sounds like the best closed back headphone you can get, whiles not having any of the flaws of a closed back cans. The utopias also retrieves detail like no other. I can literally hear things in the tracks that i couldn't make out obviously on the abyss.
What i can say is, the utopia and abyss are both so good at what they do im considering selling one. The HEK is different enough to keep it around. but the Utopia / Abyss are really good similar flavors and there's alot of overlap between the 2. I may sell the abyss, i may keep it around. Really not sure atm. Last night i heard a track on both and thought to myself.....WOW the abyss are awesome! i cant let these things go. When the abyss excels they really excel. what i am sure of though. is the utopias are something special. (Just like the Abyss).