I'm not sure other people's attitudes or experiences are much use here - in my experience some people (e.g. me!) get very nervous if they think they may miss a flight and probably over-do turning up early, whereas others are much more relaxed and would fret if they found themselves wasting an hour waiting in a lounge. I used to work extensively with a particular colleague whose attitude to this was the opposite of mine and although we flew all over the world together we just couldn't travel together to the airport: he entirely trusted that the tube would run fine and would go to Paddington to catch the last possible HEX before conformance, and I would meet him in the lounge, having got there an hour and a half before! In the end neither of us could persuade the other to accept our preferred timings owing to our differing feelings of anxiety/confidence.