yes, you still need to tend to 1st and 2nd reflection points (bass panels ala jon risch worked fine), tube traps in the corners to absorb standing waves, and i've also found that diffusion works behind the listener---i made a home-made RPG diffusor that made a nice difference when mounted behind my seat.
also, for small rooms, make sure your seat is far enough away from any walls / corners so that coloration is not present (you can hear it. just slowly walk forward from the wall while listening and you'll hear when the coloration stops. that ppoint is the closest your seat can go to the wall. ---incidentally, this technique is part of the WASP setup that wilson uses to great effect, its just that they do the listening test to mark the closest the speaker can go to the wall).
rhyno