I don't normally go this way and didn't have too high expectations but found myself nearby so thought I'd give it a try. I was very pleasantly surprised.
The XC is very short but it is what it it says it is i.e. the blue is blue (flowing and wide), red sections are a red with rollers and jumps, few rocks thrown in, (bit tame still for a English red mind) and the black is a black (two short sections) are very rocky and have a couple of quite technical drops and turns to warrant it's grading. You need to ride it a good number of times due to it's length.
I think I will return with the family as I can have play on the reds and black and my step daughter will love the BMX track, the skate park and the blue. Decent cafe too (with a pool table). You can hire bikes and helmets and it costs to ride (think it was £4.50 plus a quid for the car park). It's a bit like Redbridge cycling centre / Hog Hill set up if you been there.