Having done the Picnic and Bookham 10k this year I can vouch for how good Trionium races are! As with the others this sound like a right belter. I've just signed up and I can't wait. Well done Dr Robert on another great course.
This is not just for "serious" runners - if you like running off road you'll love it. There was a really good atmosphere last year and I think only one or two people didn't actually finish the course. As for shoes I ran in normal last yaer and that was fine....although it did take about a week to clean them.
Course last year was short sharp bursts...although I do seem to remember one very muddy hill that seemed to go on forever. Don't know if the course is the same this year. I've not done the races you mentioned but I would recomend this one- prepare to very get muddy and record a personal worst for the distance- great fun and good training for the Picnic!