I just switched from silica to cotton..
I think I like the silica better in my rda..
Can't wait to try cheese cloth or butchers twine..
In the past year, I have been through the whole gambit, cotton, peaches&cream, cheese cloth, butcher's twine, etc., etc., etc. Right now I am perfectly happy with Ecowool and plan on sticking with it for a while, I use SS mesh or rope for my gennys and have had good luck with that.
But we are all different and find different things work for each of us, and the experimenting phase is the most fun!