I would use this feature on a regular basis IF the Top 10 list defaulted to my age group.
KOM/QOM watchers are a much smaller portion of your users.
I want to see how many top 10 lists I appear on amongst my peers.

This is great. However I think you can still improve this "gaming" part of the app, which is one of the most interesting: I would like to see the results in the main page (a direct access is needed), I would like to know how my top 10 results varies across time (when they go down) so I can try to improve, I would like to easily access other person's results, I would like to see results between friends, etc. 

Also to improve the "gaming" part of the app I would open the "group challenges" to everyone, including unsubscribed users, otherwise it is quite useless. People uses other options like Garmin's challenges.