i bought the promedia 2.1 a few years back when i was looking for a sound system and it went back to the store the next day. while build quality was impressive and while they didnt sound bad the subwoofer and speakers are improperly sized. the subwoofer completely overpowers the satelites even at the lowest setting and the satelites just dont pump out enough volume. it would do you well to avoid it.
i currently own klipsch home theater speakers which are wonderful. i just think klipsch didnt think that one idea out well enough when they paired that set together.
the z623 is pretty solid set. its a good all purpose set and will likely suit you better.