I have that sub, driven off a JBL amp. It's not bad at all for the money (i paid 40). It looks a bit stoopid but mines well hidden so it's all good.
The build quality isn't brilliant, mine looks like they knock them out as quick as possible. Having said that, there isn't anything wrong with it as such.
Overall, very happy with it. It sounds quite tight in a sealed box, just what I wanted really.