Can't speak to the Mini Utopia but my experience with my own Mezzo Utopias is the same as cfb suggests--200 or so hours. The change was clearly apparent, not huge, and all for the better. Transitions became virtually undetectable and the whole sound became more uniform. I'd say don't expect a whole, whole lot.
BTW, anyone who listens, even with the doors shut and earplugs in place, to 200 hours of Barry White deserves whatever horrible things happen to his auditory and vestibular systems. Play anything at all; it doesn't matter. I have a friend who burns in everything by playing the soundtrack from the Wizard of Oz.
But then, he's over the rainbow about lots of things....
BTW, anyone who listens, even with the doors shut and earplugs in place, to 200 hours of Barry White deserves whatever horrible things happen to his auditory and vestibular systems. Play anything at all; it doesn't matter. I have a friend who burns in everything by playing the soundtrack from the Wizard of Oz.
But then, he's over the rainbow about lots of things....