I've started using it, but only as a record of my rides. I'm not anywhere near the fast guys on the sectors round here (though some of them seem a little suspect
) so I'm not bothered about trying to compete. I make all my rides private anyway. It's just a great log.
There aren't many sectors near me it seems but a couple of the ones I looked at were on public shared cycle/footpaths. I don't think it's a very good idea trying to set records on that sort of thing. They're tricky enough sometimes at a slow pace with the amount of dogs and kids on them. Probably a good one very early morning or late night though.