I heard Nola Metro Grand quite a bit at my local dealer and have heard various Avalon, Wilson at friends' place and other dealer. However, I never heard Nola in the same system as other speakers so take this for what its worth. First, Nola's finish is nowhere nearly as nice as Avalon, Sonus Faber and is a touch better than Usher and to my eyes, nowhere nearly as nice as Wilson and Magico. However, having said that, if I could not afford Magico Q3, most likely, I would end up with Magico S5 or Nola Metro Grand. You definitely need tubes, or tube like electronics for sure. The midrange is full, rich,yet finely detailed and delicate and is as good as anything I heard even above its price point. You could not hear that it has ribbon tweeter and dynamic woofers. This is only true if you don't listen to it near-field. They really need some rooms to breath. The bass in punchy, fast and surprisingly deep for 2x 4 inches woofer. The bass quantity does not match Wilson Sophia but the quality far exceeds it in my mind. In comparison to Q3, the bass is probably the biggest complain. I could still hear slight wooden boxiness. I usually think of Magico as really having no enclosure sound at all (some of my friends think that I am hearing and addicting to aluminium box sound, rather).
For my taste, Avalon really does nothing wrong but is less exciting and just does not turn my head as much when I hear them for some reason. Wilson has bigger bass and slam but less detail and definition. The midrange and high while nice is not quite in the same league as Magico or Nola. Unfortunately I never tried Wilson or Avalon in my own room to really compare. I just hear them at show, friend's place and such but they just never interest me enough to really try. Personally, if I ever have enough money to upgrade beyond Q3,I would more likely pick Baby Grand over Q5 (easier to drive, more choice of amp) or Concert Grand over Q7 (Q7 would make a hole on my apartment's floor)!.Maxx3 and Isis just did not quite do it for me.
However, this is only as far as my taste and preference is concerned. I could see other people like Avalon or Wilson better for different reasons and they would not be wrong either.