HF: good idea to re-read. Doing it now (well, after this post).
FD: It's just that it's really the first time that I've had such a situation. My usual experience of FIS is to say hello and goodbye, and listen to everyone else doing the same, thus getting an idea of who is about... No, I lie. London once told me about a Cessna they knew about travelling in the same direction as me, but I spotted him ages before I caught up. He was higher than me, going with your theory of they're more difficult to spot when low.