Basically, it's one of those "what is possible?" questions.
One thing I've noticed with various different spiritual teachers is that it seems like a personality type match is highly beneficial - for example, Rupert never did much for me, whereas people like Ram Dass, Alan Watts, Terence McKenna, Jiddu Krishnamurti I can listen to for hours. I wonder if there's something that could be done about this as well.