Not sure that's a fair test. I've used both (Superthrive for over 5 years, KLN for one year) and I'll vote for KLN any day. But I don't think your test is the end-all for the diff. I have found (for me) that when an orchid has any kind of viable roots (nubbins or otherwise) then the KLN will outperform the Superthrive hands down.