I use Walmart cotton balls. Not for any other reason than, that is the store at which they were purchased. Once boiled, all cotton is the same to me. I boil and sun dry all my cotton, seem to make it work better. Pads might be a bit easier to use, but not 10X or more better.
Is cotton the best? NO, Maybe, Yes. I prefer stainless or silica for flavor. I prefer to BUILD with cotton, and maintain attys wicked with either SS or silica. No Rewicking required with SS or silica, you can clean in place.