I must say that I have not had any issues with signing-in or logging-on for about 6 months, although recently (last week or so) I have had a few issues but I notice that there has been Downtime/Outage announcements for 4th Sep & 12th Sep. I guess they have to do maintenance sometime. They also recently upgraded the Running App that I use so I guess they are making changes to accommodate that too.
All in all though, I like the simplicity of the site, the amount of information it aggregates for me and the litttle rewards etc. mentioned above - they are motivational for sure. All I have to do is press RUN and then STOP the workout at the end, oh and RUN inbetween of course!