My serious listening is nearfield (68 inch equilateral triangle) with my computer chair about 5 feet behind. Speakers are toed in to cross between those two positions. Speakers are over 5 feet from front wall and 3 feet from side walls (Cardias recommended setup). As mentioned above I wouldn't try it with complicated speakers designs or those using high slope crossovers.
When sitting in "the" chair even kids have instantly commented on the magic. Their eyes light up in amazement. As Casler mentioned it takes you from hearing the performance in the room (normal set up) to being at the performance (nearfield). The first impression is that it sounds too much like headphones and large speakers like mine look silly/scary close. But the soundscape coherence is amazing.
Unfortunately modern recording technics are miked too close, so you can get too much of a good thing. It does help take the room out of the equation, but IMO the best listening room would be very large.
