While I am irked, like dogg, that the bass control is limited to the tri-band EQ (not having a separate line out control is just shitty design), otherwise I really like the sub.
The vehicle specific design and the plug and play aspect of the sub was a big draw for me, as well as being a GM licensed aftermarket part not messing with warranty.
The sound fills out the 'missing subwoofer' you hear, and fairly well for an 8" sub, but the enclosure and power isn't super hard hitting like you'll get with a crafted box, and well thought out amp and sub. But for me it filled the gap just right, and the install was super easy. Definitely a good icebreaker for me on a new vehicle with trim removal and such.
Cost wise, if that's a factor, if you're buying a quality sub/amp/wiring/box, you'd hit that price point or close to it pretty easily.
vi et armis invictus maneo..