Getting to tech support was a pain (the web form didn't work and I had to wait 30 minutes on hold), but once I did, they were great. The end result is that I'm sending mine back and they're sending me a refurbished unit under warranty even though I'm 10 days past the 1 year warranty, so I'm pretty happy with that. I'll be using the old Suunto T6 until then.
I did six in the neighborhood this morning on one of my usual routes. Pace was about 9:00. I finished with six 10-second hill sprints on a 6-8% grade hill (I could probably find out for sure with the accurate altitude from the T6). I've been loosely following Hudson's Run Faster and did 2 hill sprints last Mon, 4 last Th, and then 6 today. They serve basically the same purpose as strides, but they're also supposed to help leg strength.
I'm still scratching my head over the 10k.