As a result of this thread I started thinking about how should play holes. This is a corollary to TCs (?) advice about playing to the 150 marker, but I hit my 7 iron about 155-160 and under normal circumstances feel pretty confident from that distance and in. So if I subtract that number from hypothetical hole distances it becomes somewhat clear that there's really no reason to hit driver, except for longer par 4's or maybe a short par 5. A 400 yard par 4 stretches this to the limit - a 3W (235), 7i (155-60) and I'm probably a few yards short. Anything shorter than that definitely should not involve driver. Even something like a 550 par 5 breaks down comfortably as 3W (235ish), 5i (180ish), 9i (135).