LateFinals,
What altitude were you over Brize? Their CAS extends only to 3500ft.
Llanfairpg,
I believe that the last mid-air in IMC in the UK was in WW2. Mid-airs seem to happen invariably in VMC. I'm not sure what that tells you about IFR vs VFR - the big sky theory might just work better in IMC...
Tim