I do have both the Utopia OG and Caldera. Recently I've been distracted by many other things in life so haven't found time to A/B them yet. Here's some rough comparison of them + LCD5 just for a quick reference.
Soundstage: Caldera > LCD5 > Utopia. Caldera's soundstage is comfortably bigger than the other 2 and probably comparable to Susvara (I don't have them anymore).
Details/Separation: LCD5 is slightly but surely ahead of the other 2. Detail wise I think the Caldera and Utopia are very close. Utopia has a brighter presentation (although I never think it's too bright) which helps the perception of detail retrieval. In terms of separation, I think the larger soundstage is helping the Caldera, as in that the Utopia has a much smaller canvas and limited room to dissect.
Dynamics: They are all great! Caldera has the most "bass slam", LCD5 is very intense and engaging in the mids, but overall I still think the Utopia is still the most dynamic of the 3.
Tonality:
- Caldera is the warmest. The bass response on the Caldera is absolutely delicious without being overblown. The mids to me doesn't quite have the Atrium magic, but is still full and emotional. Also this along with Atrium are the 2 least "dark" ZMFs I've heard. It's still warm but it's also pretty transparent.
- LCD5 has pretty strong emphasis on the mids and could feel "studio like" at times, mostly due to its superb technicalities. It's clean, sharp and numbingly fast. Listening to albums like Discovery or Mezzanine with them is pure joy.
- Utopia has been my "daily driver" for a long time and it has become the "just right" reference for a while. The small, intimate soundstage combined with amazing dynamics and great details really is a magical blend. It's definitely brighter (but with less sibilance to me) than the Caldera with lighter bass. I'll say both are within my comfort zone for enjoying contemporary music.