I owned a 350 for a year before my 500 and it was a very good sub. Since I've moved downstairs to an almost 900Sq Ft room, the 500 seems to fill the space more evenly, but the 350 did a good job as well. The 500 has more "feel it in your chest" experience. If our room is not to huge, the 350 would do well also..

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85