It's a bit weird that you say that your not interested in what else is out there. The only real way to decide whether it's worth spending your "hard earned cash" on one, is by comparing it directly to what else is available for the same price...
Couldn't really recomend them mate, based on a couple of things.
Low power handling is one of them. Now power output isn't everything and sometimes can have very little to do with how a subwoofer will sound. You can find anything from a $100 entry level sub, right through to something well over $1000, and find that they both the the same nominal output. Obviously though they will sound nothing alike.
But when looking at an entry level sub, i find it's always best to find a sub that will handle a higher rated input power, because you can only hope to get one thing out of an entry level model, and that's bang for your buck. A sub that will play louder at that price range IMO represents better value for money.
Some lower handling subs are specifically designed for sound quality applications. The JBL allthough a low power sub, neither targets SQ, or outright SPL, making it a little hard to reccomend for the money.
That's just my opinion and my advice, if you think they sound good and will meet your needs and expectations then go for it and get them, after all that's all that really matters.
The only further thing i will add is the age old debate about quantity vs quality. If a single sub dosen't sound to you the way you would like it, sometimes adding a second one isn't the best option. If you have one crap set of speakers, adding another set dosen't mean it's going to get any better. All you end up with is twice as much crap. (I'm not saying this particular model is crap, it's just a way of putting an example accross)