I've tried the organic cotton, readyxwick, KGD, hemp, and peaches and cream yarn. Haven't tried rayon yet, mainly because I'm pretty happy with my set ups. Of all I've tried, I like the KGD and readyxwick the best. The readyxwick last a super long time and is easy to work with. I find I get the best flavor with the KGD though. My builds are usually around .5 and if I'm feeling lazy I'll throw in some readyxwick and forget about it for a while, but with the KGD being in pads, it's super easy to get consistent sized wicks that take all of five seconds to change out every few days. Luckily, I haven't run into dry hit issues yet. That's another beautiful thing about the Reo. I just squonk every few hits rather I need to or not