Vandersteen Treo in 24ftx22ft i.e 528sqft room?

Actually, I have the 1's, 2's and 3's. All are current production as far as I know. I have heard the Treo, but not next to any of the other models. The Treo's are excellent speakers but I'm pretty sure they were made for appearance purposes. Given the overall design of the traditional Vandersteen's, there's really no reason that using a full box would yield any sonic benefits over the other models. I didn't do extensive listening to the Treo's, but it seemed to me that the imaging was not as good as my 2's or 3's, and the scale (image size) was definitely smaller. Beyond that, I really don't want to comment too much because I didn't have enough time with them to do an all out review.

My 1's are not in use right not but I have the 2's in my main system. Setup properly, they can hold their own with just about anything. I have a pair of Wilson Cubs in another room. Aside from the Cubs being a little more efficient, there's really nothing they can do better than the the 2's. I also put them next to my friends 802D's and they were able to do most things better.

The 3's are definitely an improvement over the 2's, they just don't sound as good as the 2's do in my current listening room. So the 3's, for now, are set up in a condo I have in another area. I plan to move my main system to a bigger room. When I do that, I'll move the 3's and bring the 2's to the condo.

Getting back to your origional question, from the Model 2 and up, they should all sound great in you room.

Geek, I've heard earlier versions of the Model 2 in rooms larger than yours sound just wonderful. In fact, due to the physical design of Vandersteen speakers, I believe they benefit from placement further away from both rear and side walls than most other speakers.

The Vandys with built in powered subs can be better than most other speakers due to the fine tuning for the room which can be achieved. Still, I expect one advantage with either the 2 or 3 is the ability to place them for optimum performance within the room, then locate the Vandy subs separately for their best performance. Optimum mid-range spaciousness and openness will not necessarily be the best location for smoothest bass response.

I think the Vandersteen Treo would be fine for you. I would highly recommend giving Jonny R. a call at Audio Connection for some friendly advise on the Vandersteen line of speakers.

How about the comparison of TREO vs. QUATTRO?

Old thread, but they keep showing up when I make other posts, lol. 

First off I do have Treo's.  I think I still have decent hearing, lol.  I auditioned the 3's vs the Treo's.  It wasn't close for me.  The three's go deeper, but not with the quality of bass that the Treo's give you.  The bass is plenty for rock as long as you have the source to send it to the amps that can handle it.  It all depends on what's upstream.  

The fact that the Treo has a gorgeous box within a box instead of a sock doesn't mean it doesn't sound better.  I have the original Treo's which is the one the OP was asking about.  I'm currently selling my Treo's to get the Quatro's.  I need the tunable bass in my room, hence the upgrade.  The Quatro CT vs the Treo CT is about scale.  By freeing up your amps from having to worry about anything from 100k down, the sound will be better.  You can push the Quatro much more than a Treo, however if you have a pair of Vandy subs for the Treo's, then you can get 95% of the way there to a Quatro. The Quatro is the best value in his product range I think.  For 14k you get a true full range powered speaker that personally competes or beats nearly anything I've heard from 30k down.  I've heard a ton of speakers and Vandy's aren't the only one's that make great speakers, but the value is there in spades I feel.  

Z, refinement is the true difference between the 2 or 3's and the Treo's.  I've run all of them with an Ayre AX-5/Twenty, Empirical Audio OSDE/SE fully upgraded, Steve Nugent rebuilt Mac Mini server with Paul Hynes linear power supply and SSD with all high rez music recorded for shows and even better a Basis TT with Basis arm and Benz low output Glider cart run through a Rhea phono. Everything is balanced with good AQ cables and 8' AQ Castlerock speaker cables.  My system is pretty darn good and show's off the Treo's very very well.  The 3's aren't even close in refinement, but are still a great sounding and fun speaker.  I get plenty of bass for all types of music.  JMHO