In relating to distance calcs and specifically the impact of rests/stops/walk breaks. As I learned with earlier replies, recording is initiated with a "typical running" stride rate for 5+ strides; it stops when there is essentially very little movement for 240+ seconds. Generally, I like that recording continues when there are walk breaks (100-120 SPM) or brief stops. In looking more closely at the data and others' responses, it seems to be that the recording rate goes way down during such walk breaks. This doesn't allow the walking data to be properly visualized and also seems to make it hard to see the walking versus the running metrics. In other words, the walking (or stopped) segments and running segments get smeared or averaged together. This creates issues including problems with the distance calculation. Seems like it would be better to keep the recording interval similar/same to that used while running. Given that walk breaks and stops/pauses/waiting tend to be short, it doesn't seem like much memory/battery/capacity can be saved by lengthening the recording interval during these periods. I'd say keep the record rate up until the end, it will make the data easier to sort out. After all, true inactivity for 240+ seconds stops the recording entirely, thereby saving memory/battery.
Agree that it is hard to make the device satisfy all. Personally, I'm not too concerned about having walk breaks or short rests in the data -- I'll be able to see where those are in the time plots. Of course I'm not a running "purist" -- I run moderate paces on trails and typically walking/resting at times is part of my run. Also, unlike others, I don't worry about the distance being off a few percent for a 5-15 mile run. Many of my trails have trees and switchbacks and as a result, the GPS distance if often short by at least this much (5% or even 10% overall on a typical run, and 20%+ on specific, heavily wooded subsegments when the trails are twisty and I'm moving fast). If I'm super curious about accurate distance, I look add up segments from a high-quality local trail (hiking) map.