I would not be looking to power Utopias with low to moderate power tube amp. I have heard Moabs and a few more recent Utopia line speakers, and my opinion it is pretty lopsided. No speaker is an island though, you have to have the right gear.
New to me speakers
Focus Nova Utopia or Coincident Extreme Reference , both 10 years old, or new Tekton V18 ? Currently have Double Impacts and Wyeteck tube amp and pre. 32 by 30 wood panelled dedicated A frame room.