I had a look but I carry my laptop to some meetings anyway so need a more book like form factor (depth is important). I looked at the Stylistic slate only tablets too.
Irex seems to be the only candidate but their response to be yesterday (to my email query) was very non-committal and seemed to abdicate responsibility for its effectiveness. Not encouraging especially given the huge amount of negativity about bug software and stylus lag during notetaking.
My heart says give it a go, my head says avoid!