I've had a flick through the workshop list for the convention and am feeling a little overwhelmed to say the least!
hello adrian,
i would not worry too much if i were you.
if you're prepared to be up and ready for 8am and stick around 'til around 8pm, i think it makes little difference who or what you see .... i am certain, you will find that anyone invited to speak at the convention, will be truly inspirational and a tremendous help to your photography in general.
.... and of course, specialists in your particular 'field' would obviously be an added bonus.
good luck with your plans.
kind regards,
david