I went the first year it was on and went to the finals but its very expensive for what it is I found. Its a course of coloured and x country style fences with a bogey time I seem to remember which is quite fast.
Lol it wasn't with us either and we won our section but I really was dissapointed with it. I used to do arena classes at Addington which were a dressage test, a showjumping round and then a x country round over rustics in a seperate arena and that was £20 a class, much better value I thought.
Actually, Lime Kiln Farm runs similar eventer trial classes- fastest clear wins. Dunno if they keep going through the summer, but we went and it was brilliant!