It's not about the heatsink. Coollaboratory's Liquid Pro and Liquid Ultra are electrically conductive. This means that unless you're very careful with the application, if even a bit of it flows down into the CPU socket or on the CPU die (under the heat spreader), your CPU and potentially your motherboard are dead. IMO they do not offer a tangible benefit if you don't have a massive watercooling loop, so just stick to something like ARCTIC MX4.