Look for my QOD Max thread. It chronicles my DIY BKT journey over several months. I've been frequently BKTing my own hair since 11/09, and my hair has done nothing but grow grow grow. I have not had a haircut since November, and I have no split ends. None.
My hair is super-duper baby fine and fragile, and I have had damaging highlights done twice since November. I now use a mixture of cassia and henna to color my grays, as the highlights are just too damaging to my baby fine dark dark brown hair.
The BKT itself has not damaged my hair. I can't say that no damage occurs with using the high heat iron during the BKT application process because that's just the nature of the relationship between high heat and hair. But, like I said, I have no split ends, no appreciable damage. I get some breakage, but that's because my hair is fine like a baby's hair and has been lightened significantly during the highlighting. My hair is down to my mid back--a little longer than in my pics--and I L.O.V.E
. it. It has changed my life. I BKT my roots every 3-4 weeks and do a full-head every 3 months. I don't wear my hair straight; I wear it curly since the curls are big and loose with the BKT--this cuts down on damage significantly. But, it's very very easy to straighten my hair. All I need is a blowdryer and my hands. The curl is so loose, I can pull it out with my fingers. I am a natural 4a/3c, now a 2a/b with BKT.
Search for my thread--I can't remember the title, but it has QOD Max in it. I just bought QOD Gold, but I still have about 1/3 of a bottle of QOD Max. It lasts a long time. And what a $$ savings!!