Film everything. I always do. Most films I never watch. But I rename "interesting" films to names which identify what they were about, and those with names like filmxx.ahf can be deleted after a week or two. My film folder is still only 377MB in size and I haven't even been deleteing the old films for the last few months.
Don't cry cheat! You would need to have reviewed the film yourself to see what happened. I remember one time egressing from a fight in a 109G10, and being worried about a YAK in my 5 o'clock. He was at 800 yards or more, when BOOM - I'm dead. Hell of a lucky shot, I thought. Reviewed the film and doh! There was another plane (can't remember which type, but something very fast) in my low 7 that I hadn't seen.
MetaTron: I used to have that same lock up problem when starting the film recorder. The screen would lock for many seconds, and in most cases AH would get aborted and I would crash to desktop. It only happened when starting the film recorder the first time in each AH session. I was able to get round it by starting the recorder in the tower. But since upgrading my PC (Asus A7N8X DLX, XP2600 etc.) the problem has gone away.