While I can understand and even expect that the Utopias have better resolution than the HD800S I disagree with your assertion that the HD800 S cannot render classical music properly due to being blurry. Just because they are not as good does not mean they are not doing it well. So I suppose unless we spend $4000 we can't hear properly rendered classical music . Not true. A pair of $80 Grados do great with classical music. And yes I have heard classical music live many times.
I will have to agree with you on the first part of this. Also finding reference quality classical recordings is really a nightmare - especially those that retain all details while still retaining a black background, e.g. inaudible noise floor, and recorded at a location with excellent room acoustics. Not to mention the performance of the orchestra. These are all aspects, which is in my opinion too often forgotten even on many so-called audiophile releases.
I could perfectly live with some of these releases on my HD650 or the Grado HF1 which I'd call blurry and fuzzy by comparison, with HF1 the worst of them. But definitely not for the HD800S. IF the recordings are of proper quality. I can recommend something like the collections "Ports of Call" or "Reveries" by Reference Recordings as excellent recordings with an excellent conductor and orchestra, even though neither of these were recorded like yesterday.
EDIT: Just for reference, I have NOT heard the Focal Utopia, but I plan to do at some point. I don't doubt the Utopia is better at some points, but my point was just that we need a frame of reference of the recording itself, because a lot of these are simply just not good recordings.