To get faster and loose more weight in less time while still enjoying food. I'd like to be as fast as I was at 25 where 20 miles was a lunch hour ride and 5:45 riding was a nice hilly century instead of 8 rides totaling 96 miles over 4 days.

That comes from riding as hard as possible over various intervals with enough easy days/weeks mixed in to make the load sustainable.

Data makes it easier to figure out where my current limits are for planning and what I can tweak to make things work better. For instance, I found out I could ride hard two days in a row if I tended to ride at 90-100 RPM instead of 80-90 RPM although I'm equally comfortable at either cadence range.

While riding power numbers tell me how hard I'm working within seconds, regardless of how fresh or tired I feel and what's happened to heart rate from overheating and dehydration.

It's motivating to see quantifiable results. Looking at time doesn't work because of hitting different traffic lights. Speed isn't even relevant over the same course due to changing winds. Watts over the same time interval are pretty representative of performance on different roads regardless of whether the hills and wind are working for or against me.

I'm also an incorrigible geek who likes gadgets and mechanical toys.

It's typical for cyclists training seriously. Most probably don't try to get quality miles commuting, but I don't want to spend an additional 2.5 hours a week in my car or 7-8 hours commuting at a recovery pace so I can do those 5-6 hours on other routes.