The Mezzos should please you if your other components in the chain also deliver your stated preferences. Mezzos are revealing, so if any of your components, or interconnects lean towards the brittle, dry or etchy side of things, that's what you'll hear. They are NOT romantic; However, they can be spooky real when properly fed. In my experience many speakers with "silky" highs are actually imposing a signature distortion on the music. It can be pleasant, especially with recordings that benefit from this sort of "treatment", but in the final analysis you end up missing detail, presence, breath, imaging i.e. reality. I guess the price you pay for accuracy is Garbage-in = Garbage-out. In any case, the bass is strong and accurate as well - very fast, too. No peaks or dips I can detect, although they are not the last word in depth. What you get is powerful, rich and linear but you can go up to the Utopias for even deeper bass with the same character. Finally, the Mezzos (and utopias) are a steal right now. Mezzos used to list for $14K, and have been reduced to $10K in order to clear inventories before the new version is released. You can find them used for $6k on this site and others.
I have no experience with the Alons.
I have no experience with the Alons.