That adds another $15 cost ..... From my PoV, I don't see the sense of spending $110 ($95 + $15) to get the less cooling than you get from a $65 air cooler which can't leak on your components....and yes it does happen
http://www.overclock.net/t/1440506/my-corsair-h60-exploded-water-explosion
Don't get me wrong, my system is water cooled but not with an AIO. To my mind, to offset the risk of putting water inside your system, you should get something in the way of:
1. Decreased Noise .... AIO's don't have a hope of accomplishing that
2. Decreased temps ....120/140mm AIOs don't do that
The 240/280 AIOs w/ 1500 rpm fans will match the better air coolers in both noise and temps. The ones that are capable of topping the better air coolers, need 2700 rpm fans to do so and that saddles you with noise levels associated with modern vacuum cleaners.
In today's market ....
$25 - $50 ..... best solution provide by a Hyper 212 air cooler
$65 - $90 .... best solution provided by a Phanteks PH-TC14-PE air cooler, Noctua DH14 or 15, Cryorig R1
$100 + .... best solution provided by an OLC like Swiftech 220-X to which tops all of the above thermally, is 20 dbA quieter than competing AIOs and you can add GPus, MoBo Blocks and RAM to the loop, simply by adding the appropriate block.