laureal, your DH is right about all the variables but I agree with you that some attention to numbers helps you measure milestones and set goals and objectives, which IMO aren't bad things. You should be commended for wanting to improve, after all. Do think about joining group rides, though. In my own experience nothing will help you improve more in speed, endurance, confidence and knowledge like learning to ride safely with a compatible group. Ask around the lbs's and local recreational clubs to see if there are group rides with variable paces and distances and that welcome newbies. For example, our local rec club has a year-round Saturday road ride that attracts everything from occasional riders on mtbs and hybrids to hardcore road racers. Each week the rotating volunteer ride leaders try to match up newbies (experienced or not) with compatible riding companions or groups (if they're experienced enough to ride in groups). The basic route is a flattish 20 miles with hilly extensions up to 100. Something for everyone. It's a good way to meet people and learn, and if you can find a ride like that, I know you'll enjoy riding more, and you will get faster - if that's what you want to do. Try it just a couple of times - and good luck!