I don't use clay anymore. I would suggest two things if you use this product: use their "glide" lube product as its different from other lubes and detail sprays, and most important... Use the fine grade pad, and make sure you break the pad in before touching your paint. Break it in by doing all glass surfaces first. If you don't break the pad in, it will likely mar the crap out of your paint. Trust me, this product does a heck of a job but you have to use it properly.
You can also use it by hand which works well if you are nervous about putting power behind it. It saves tons of time.