Does anybody really believe that powerpoints are a good idea for most 1:1 briefs? Surely they should primarily be a dialogue between the instructor and their student, and as such the interaction of a developing image on the whiteboard is far more powerful than the relatively unchangeable nature of powerpoint slides is much more powerful as a teaching tool.
(Personally I like using an A2 artpad and fibre class pens - then my student can keep the sheets if they wish, but the principle doesn't change).
G