RD, besides Mark's rather practical thought about protection from prying fingers(or paws), keep in mind that the distance from the driver cone(not the back of the enclosure)determines room reinforcement factors and room modes are at a maximum right at the wall surfaces. With the driver maybe 1'-1 1/2' closer to the walls when facing them, excitation of the room modes is a little stronger and would result in slightly stronger bass.

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Enjoy the music, not the equipment.