If you're thinking about the one about 15m south of Oxford, I wouldn't bother. Despite using all the means of contact on their various websites, sending countless emails, leaving numerous answerphone messages and filling in webform enquiries I never heard anything back from them at all. I know some of the guys will be away on ops at times but after about two months of trying I took my several thousand pounds and spent it elsewhere. (And I used to be in the RAF!)