I had this brake kit fit a week last Saturday. I haven't really had chance to test them yet, but am going to Croft on the 7th so I'll test them out there. Here is a couple of pics taken at AKS after fitting.
How did you get on mate?
Croft went really well, brakes performed amazingly over the standard 345mm brakes, no brake fade at all in the 20min or so I was stopping out for.
I'll be going again when the weather gets better about April time, hopefully by then I'll have a Wavetrac LSD and light weight wheels with track tryes.