I'm considering used Vandersteen Quatro

I would actually audition the Vandersteen 2Ce Sig II’s before you move up the line to the newer speakers (e.g. Treo). It should be a relatively easy load to drive, much easier than the 3A Sig (which I own). The 2Ce Sig II’s dig fairly deep into the lower octaves and don’t have the need for a crossover. However all Vandersteen speakers are made for biwiring and the barrier strip requires spades less than 0.5 in wide, so you may need to reterminate your current speaker wire for best connection.

One other thing to mention - if you decide to purchase Vandersteen speakers, follow one of the speaker placement methods outlined in the manual. Read it carefully and make sure that measurements are exact. You will be rewarded immensely with your patience.

@jetson - I think your wife will probably have an issue. The Vandersteens are bigger and will look more physically imposing than the Totems. My wife doesn't care too much because the stereo is down in the basement. Is there no other room you can use? If you've got the land, perhaps you can build a listening shed out back. (I believe Michael Lavorgna of AudioStream has a barn on his property for this purpose.)

In any case, my room is about 22' x 13.6' x 8' and I have the speakers firing down the long wall and about 24.25" from the back wall - measured from 'acoustic center' with the distance calculated using Vandersteen's 'odd dimensions' method. It's what sounds best so far to my ears while also accounting for room layout limitations.

You might get just as good (or better) results with a two-way standmount speaker and subwoofer.