I pretty much just have one ride page.. Time, 3"power, Cadence, HR, Speed, Distance (and grade). I sometimes use my lap page which is lap time, Avg power, 3"power, cadence, hr, avg hr, (and lap number).
Having speed can be useful if you're in a break. For example if you know the pack was doing a certain speed, I've found you need to be 1.5-3 mph faster when establishing. I don't really look at my computer that much in races though. Small or solo breaks, sure, but in a pack keep your eyes up. Racing on the track (no computers allowed) helped hammer that home.