i own 2 of these and they are very good for the money. i paid 58 dollars for each and they are way better than my old sonys. They sound very well even in a ported box. For someone starting out i must say they are a good subwoofer to start with. There are much better subs out there, but there is nothing that is horrible about this sub.
the sub is very reliable and very durable. i have only had one sub broken but that was my fault 100% (knee hit the cone when i was lifting up the box)
overall i give the sub 85/100