After hours of comparison of the Clear and Utopia, I decided to buy the Clear.
In back to back comparison with quick switching, matching volume by ear, and matching music segments, I subjectively find the sound to be very similar. To my ears, the Utopia brings out detail slightly more readily, but at the expense of a treble bite which sounds a bit artificial to me. The Clear sounds a bit smoother, which it makes somewhat more versatile. I like the bass of the Utopia a little more, but the difference is small.
Listening to a wide variety of tracks, in terms of subjective preference, I preferred the Clear as often as the Utopia, and it was usually pretty much a tie. So even setting cost aside, I can't say that I prefer the Utopia over the Clear, and when cost is factored in, the Clear is obviously a much better value (for me). I actually find the Elear to sound very similar to the other two also, so that would arguably be the best value of the three, but I prefer the slightly better detail of the Clear, and the case and cables with the Clear are a nice perk.
If others are comparing and deciding between these three headphones, I encourage comparing them in various ways, including using quick switching. I was surprised at how small the differences were, compared to my expectations. I didn't have a budget limit in making the decision (and I was offered a good deal on the Utopia from an authorized dealer), and really wanted to get the Utopia in the hope that it would be noticeably superior to the other two, but my ears told me that the Clear is the best choice for me.