Vandersteen Quatro: more comments?

The Quatro's are an excellent speaker period. Tonality is spot on if you base it on what real instruments sound like. Soundstaging is pretty much as good as it gets. This is probably their #1 strength overall. Bass perfomance is not overblown but is is quick with excellent resolution.
You might ask, "Resolution in the bass?" Yes, they do an excellent job of allowing you to follow bass lines and a definitive difference between kick drum and bass for example. No subs required here!
The bass may sound a touch lighter than ported speakers. These do not emphasize the bass at 40 or 50 hz. They are pretty flat down to the mid 20's and offer sealed enclosures which I have always felt performed better than ports.
IMO, this is the top speaker in the Vandersteen line. (I have owned every model in the line) The only caveat is you do need top notch electronics to hear them at their best. Also, setup is paramount. It takes some doings but worth it. The bass equalizer controls can be time consuming for setup but not really that difficult.
Finally, you would have to spend a lot of bucks to better them and then I feel the sound would only be different.
I had the 5a's but switched to the Quatro's for their smaller footprint and better room integration with what I have.

Well, I don't really know how to answer that. They don't have that bang, bang quality of some speakers (inaccurancies in my book) but with the proper power, I think they will sound very realistic. They are accurate transducers and therefore present with whatever the source delivers. They will play plenty loud with what I consider to be appropriate dynamic swings. Because of the inline filters required, the main portion of the speakers doesn't work your amp hard and dynamics are improved. With the built in sub system (if you want to call it that) they are very capable of delivering any source with authority.
I agree with an in-home audition. Only then will you be able to tell if they are truly for you.
One additional note, the wood version is said to "Sound" better than the cloth. I don't know to what extent. I like the wood myself but there is a substantial price difference. I'm sure you've read Vandersteen's FAQ's on his website and can get dealer input. Hope this helps.