I think it depends on a lot of factors. Some folks really enjoy the data side of things. They want to know as much as possible and track as much info as they can. Others just enjoy riding around and are not really concerned about data. In my view, both are fine.

I am most interested in total miles. Average speed runs a distant second. The key I have found, is to ride w/ folks who share a similar outlook. To me average speed is all inclusive from when you start to when you finish. If you subtract out stopping for lights/rest etc. in my view, you are fudging your aveage upward. My average speed is about 14mph. Not fast by any stretch but it works for me.