Bags:
I used my OMM Ultra 15L on this year's Fellsman (my first but hopefully not last), and that was amply large - I fitted my full kit in it for this year's OMM. I wholeheartedly agree that side-pockets are great for food, and a water bottle holder on the side is good. I might condsider getting something smaller, especially if it fits well when only partly full. I did, however, take way too much food for the Fellsman - probably well over a kilo... I didn't weight it - so I will take less next year. There is plenty available on the course.

Maps:
I thought that, for kit check purposes, you needed one of the specific combinations of maps that they mandate on the Fellsman website, so therefore print-outs are not sufficient (although might be useful to take as well). I took the OS maps, although didn't need them much as we got most of the way round in the light (and then the way was pretty obvious).

Robin