There is no reason to not use the pads, they do not adversely effect the performance of the heatsink. The Slk800 is hands down the best heatsink on the market, closely followed by the Sk7 and a few other high performance Heat sinks. I got a drop of 1C when I went from the slk800 to the sk7(the clip on the sk7 got lazy) and at $30 on sale I couldn't turn it down... just to let you in on how good it is, the 1600+ in my sig is running at up to 2.0V at 51C max under load on a pretty quiet 50 CFM fan.