That blog does have reviews from Brent Butterworth on occasion for subs, those are more thorough and include measurements, this one appears to be a very lightweight review (maybe just to please a sponsor), and from their description seems they rated it a bit higher than it deserved, but without measurements, its just another subjective review.....most of which I generally find useless.
The difference between this and a better quality sub would be apparent IMO, especially at higher spls and at material with lower frequency content; the Polk sub doesn't dig very deep at all, -3dB spec I found is 34hz (subs to my way of thinking should have at least a -3dB point of 20hz), and who knows at what spl or distortion levels. Depends on your use as to whether you may be satisfied with something like this. If obtained at a big enough discount I suppose the value of the Polk would be more acceptable, but I think it's overpriced at MSRP, maybe at the $150-200 range.
We are spoiled here in the US for sub choices, though.
