I found out about Buteyko from a surfing magazine which raved about the techniques success. I looked into it and found out that a course was to be conducted in my home town soon. When I started the course I was still sucking on the Ventolin as if it were air itself. Halfway through the course the instructor said try not to use Ventolin. At first it was sort of hard to break the habit, but I didn't use it. Buteyko took hold of me from there on, everything got better. I haven't used any asthma medication since; on the very rare occasion since, that my airways have started to tighten up, I listen to what my body is telling me and so I shallow breath.
Since using Buteyko I believe that I have had better concentration, which could be due to more oxygen getting to my brain. Another benefit I have found with breathing better is significantly increased athletic performance. Prior to Buteyko I had average athletic ability, however, I am now a competitive triathlete, and runner. I have won a number of mountain runs breathing only through my nose, which becomes quite natural after practise. However, because I exercise so much I do slip back into over-breathing a bit; to counter this I shallow breath as I need to.
Overall, I have to say that the change to my life because of Buteyko has been revolutionary, and I recommend it to anyone, even people without asthma.