HG converts to sailplanes

Any ex or current hg's care to comment on their experience
getting a sailplane ticket? I have a friend considering
this, he is a very experienced HG type...with zip for
powered or sailplane experience. I explained to him
that he quite likely will be able to out-thermal his
instructor...but that is not the point for trying to
get the ticket. I figure things like trying to figure
out what to do with your feet, and staying behind the
towplane, may be two of the more challenging aspect
of this. But I don't hang glide...so input welcome.