like accord man..i say go with the adire audio brahma. the lowest distortion rate of any sub right now. offers very high excursion which is good for SPL too. not to mention the flattest BL curve of any sub. very flat and unpeaky like other sub.
or you can get the elemental design SP series sub. they should give the W7 a run, for half of the price
audiomobile EVO-R is also a great contender against the W7