I just received mine yesterday, and will be building it soon. It's really quite a nice little unit.
I'm a pure Genesis guy, so have tons of SS mesh but hardly any silica on hand, so I'm thinking of trying the existing mesh and/or microcoil + cotton.
For cotton... are those of you who have tried this, are you using a little piece of cotton from a cotton ball, or cotton yarn? I ask because I can see where flooding could become a concern...
I'm using rolled cotton, which is similar to cotton balls. The oring over the wick, holding it in place has helped with leaking. I think I still have a small leaking problem, but its not coming out of the air hole like it was before. Just some minor tuning I'm thinking.