I suspect they meant that it would be better price-to-performance-wise to buy an Intel i5 processor and use air cooling versus paying for a cheaper AMD processor and spending more on water cooling. However, it appears you've already got the AMD CPU, so that suggestion would be pointless. The NZXT Kraken X61 is a dual 140mm (280mm), so that's probably out of the question. I'd say reading reviews on newegg/amazon comparing the various 120mm water-cooling options would be one way to gauge the long-term quality/reliability of what's out there. Presumably there are a handful of sites that have reviewed said coolers as well, and those could be used to gauge relative performance. Honestly, unless you're really trying to push the limits of your CPU, you may be better off with a good air cooler a la Noctua NH-D15, as the performance will likely be as good if not superior to a 120mm aio.