I do it - we have a JumpX league - which I am currently winning - woo hoo!!! and JumpX competitions. It's great fun, can be at various levels, great confidence builder and if it's anything like our local venue run by a right nice bunch of people. Can't recommend enough!
I went to Foxfield Farm a few years ago with Catembi. He came 2nd & won a sack of carrots! The course is quite flat though...from what I've seen on H&C tv, the Grange Farm one looks more interesting, with water, etc. There was no water at Foxfield Farm when we went.
I did a training day at Foxfield and I'm sure you'll have a good day there but if you can get to Grange Farm then the course and facilities are loads better!
I saw it on horse and country channel on sky a month or so ago. Never even heard of it until then. Looks fab. Cross country but a "bit safer" if you know what I mean. Well safer for me as the jumps are a lot smaller.
I went to Foxfield had a jumpcross lesson was really really good.... the only dissapointing thing was didnt have the water finished when we were there... but would defo do it again lots of fun.