Better than stock but not as good as a real setup. At full retail price I don't think they are worth it for what you get. If you can find a used one or get a really good deal and are just looking for a small upgrade then go for it.
I have one and it sounds great, nice tight bass. I am pushing it with a RF300 Watt amp and it rocks. Only thing it I can not fold that side of the seat down anymore, but it fits nicely and is out of sight out of mind.
Will is win a sound off, No, but it will make some noise.
