As a fellow Vandi 3A sig owner and a firm believer in speaker placement and listener position, it's a real pleasure to read your very detailed description of your listening room.
I really feel that a properly set up moderately priced system which is well matched to the room it used in can sound as good, if not better, than a poorly set up or mis-matched room/system costing much more. A very good friend of mine as a wonderful system which sounds great when I sit about 5 or 6 feet back from his "sweet spot" - the speakers are just so large that the sound overpowers you when you're sitting that close.
The 3a sigs really benefit from a good 8 to 10 feet of distance for the sound to blend and bloom. I also have a listening room which opens into another space so there is no rear wall and do think that really helps the sound open up quite a bit.
I'm hoping to post my system on Audiogon in the near future but until then a few quick details - Sim Audio amp and pre-amp, Linn LP-12, Grado cartridge and McCormack universal disc player along with a single Vandi sub and Cardas cables - all making some wonderful sounding music together.
Speaking of music, what kind of tunes do you spin on that beautiful table of yours?