The single most important job for any A/V product is not to commit a sin of commission. In other words, where it deviates from "ideal," it should omit things (extension, headroom, nulls of the frequency spectrum) instead of adding things (distortion, peaks of the frequency spectrum, smearing). So the "accuracy" answer is clearly the most important. Second most important, is accuracy under any situation. When the War of the Worlds in DTS has high SPL under 10Hz, then the electronics needs to know what the limitations of the sub are, and protect it not just from distruction, but from committing sins to the sound. Better that it not be there, than flabbing up the place.
Once you get the situation-proof accuracy nailed, then the quantity, price and aesthetics come next. But 90% of the money needs to go towards the situation-proof accuracy, IMO.
Cheers,
Chris