Thanks all - some useful guidance in there. Current day to my understanding min RVR is 800m due single pilot IFR ops. Either way, the cloudbase and RVR don't concern me too much as long as they're in limits (a buffer for potential variation of marginal conditions is a discussion point) and as noted there is a VFR circuit involved. I was looking for more understanding of what an examiner would judge useable as the poor bugger obviously has to look out and stay safe in uncontrolled airspace at some points and also needs to safely conduct general handling. I'm close to test but doing weather briefings each day and tracking what's a go/no go day at this inclement time of year. Understood it looks good at present though my view is changeable light winds are possibly more of an issue with runway changes etc along with increased traffic. Fingers crossed on the day of reckoning for a generally poor but stable day with moderate winds and some SCT cloud!