Notes
I ran from home today and wanted to run some on my trail, so I turned off the GPS signal on my watch. These splits are calculated based off cadence from previous runs. While on the trail I doubted their validity since I felt like I was going slower than that, but it didn't matter because I just wanted a recovery effort, whatever the pace came to. However, I used road landmarks on the last 2 miles just to see how it would the watch would fare and the pace actually matched up right on. Splits were basically the same so I know I didn't speed up from the trail much (or at least, speed up my steps), and based on past experience and now a map, the actual pace was right under 7:20. So SCREW IT, I'm leaving these splits!
This certainly doesn't prove that the cadence-based distance calculation is perfect, but I have to admit I'm fairly impressed. Should continue to improve the more I use my watch (with GPS on and measuring well, that is). Wasn't doing well on the track yesterday (had each 1600 as ~0.91mi), but I wouldn't expect it to be perfect since I don't use GPS at that pace. I guess around easy/recovery paces it has some decent data to work from at the moment.
Just more fun GPS scrutiny