First of all thanks for the replies, it's very much appreciated.
I think I should clarify, I haven't let my IR lapse and would not do so, since most airlines stipulate that you should have a current IR and multi engine rating before applying, I hope that answers your other query Q.
What I haven't done is practiced IR flying too much since, sure I've done a bit, but I haven't pushed myself, and haven't been tested in any situations, except one where the wx closed in behind me and I flew an ILS back in (two months ago). Sure you can be current, but are you in "current practice"?
My plans now are to fly with IR instructors throwing all sort of crap at me, as much as I enjoy tootling in singles I'm going to have to splash out on quality flying, some P1, some with an instructor just to keep me on my toes.
What is annoying is that in my IRT the examiner praised me on my IR flying ability, one of the best he's seen, he said. Four months later my IR scan has become non existent and this has cost me a jet job.
Complacent? I guess so. My fault that I had a golden opportunity and didn't grasp it with both hands, despite appearances I have beaten myself up about that.
Am I going to dwell on it - no, no point in that, take it on the chin, dust yourself down and start all over again. Next time I'll be ready for it.
RVR - good point, when you do need to use your IR for real it's normally because you have to. I thought that two months ago when I got caught out.