Can't say much about Superthrive, KLN, or other products like it, they may just be hype. Nobody's done an actual study on these products.
You can use moss on the mounts, but sparingly, and only 1 layer thick. Have the roots go on top of the moss. You can also put a few strands of moss over certain parts of the roots. By no means whatsoever, should the roots be completely covered in moss on the mount though.