Haven't really read ALL reply's so excuse me if I repeat something..
Someone mentioned it's not worth it because of the added heat? Well I read from a respected member on these forums that the extra heat would be so minimal that you couldn't evan tell, and taht if anything were to be effected by it, it would be the extra restriction by the block and not the heat.
If you aren't really going to OC that much or evan moderate, you really don't need it at all, atleast in my opinion.. But i'm not all for against it, as a matter of fact am considering making one myself. If you think you want that extra quietness or just think its "cool" go for it, just don't go crazy spending $40 on something you don't need, make one or find a cheap used one. If you happen to hitting the checkout button on a $40~ chipset water block, immediatly move your mouse to the NW of your screen and HIT THE BACK BUTTON REPEATEDLY! If you are looking for quietness and can't find a water block in your price range just get soemthing cheap on air.
Edit:
meThinks = "You have passive cooling";
if (meThinks == TRUE) {
meThinks = "To be on the same side cool it a little more depending on how large the current HS is. If its small/aluminum POS you should upgrade it..";
}