I've had a few of the lower end models. I had the haydn, that was the first thing I ever bought from a real audio shop. When Best Buy dropped the line in about 2011 I bought a full surround set of demo models for a fraction of new. I've currently got the Mozart Grands hooked up as computer speakers. (Cambridge DAC Magic and Creek 5350SE.) I think they're fantastic in this application. In my experience they're more room and placement dependent than most speakers. I compared them to my Thiel 2 2s in an old living room and I thought the Thiels embarrassed them. The Thiels were much clearer and had a good amount of punch where the small drivers in the Viennas just couldn't do it. They also sounded pretty strange in there, I have to think they've got a strange off axis response that becomes really obvious in a more reflective room.
I was told that they're optimized for Europe where most houses have smaller rooms that are more solidly built. That was a number of years ago so may not be true of newer models. The ones I have definitely sound better when you're sitting fairly close and are in a room that's on the smaller side.