Comparison time:
Leikr with sw 1.10.28: https://www.endomondo.com/workouts/374896448
6.61 km, 42:30 minutes
Endomondo on iPhone 5: https://www.endomondo.com/workouts/374884064
6.62 km, 42:55 minutes
The time is a little off as I had to start the iPhone app before putting it into a belt pouch, and then couldn't stop it till I had taken it back out. The time difference is mox-nix because of this.
The distance measurement was interesting - throughout the run, I would get a vibration on my wrist for each km from Leikr (autolap was on), and at the exact same time I would get a notice from the Endomondo app for the same km. So Leikr was spot-on with my iPhone.
Obviously, I don't claim the iPhone/app combination is the gold standard of GPS reference equipment, but it seems to be a good enough tool for the masses who who can't be bothered to pay for a dedicated GPS training watch . . . so I'll say that "good enough" is good enough.
Interesting note: pedestrian underpass at 3.47 km and again at 6.15 km. I did not lose all satellite reception going through this steel-lined concrete tunnel, and immediately had 7 or 8 satellites upon exiting. Looking at the Leikr plot, I can see that the tunnel caused a sideways error in position with a complementary spike in pace at the 6.15 km point. The rest of the plot seems consistent enough.
On the other hand, I am still having random difficulties syncing the watch over wi-fi, but I have been in touch with Team Leikr to address that issue. As others have mentioned, it would be a very good feature if I were able to download my workout data directly to my computer, or to have unfettered access to the data without it being first filtered by Endomondo, Strava, or MapMyRun.