Personal Records

There isn't a report that searches for the fastest times logged in your training log. This would have to be a custom report as everyone's idea of fastest training time would be different. It could be dependent on the distance, route, equipment used, time of day, time of year etc.

There are two options though: the Personal Best fields in the Personal tab of your Training Log Settings or the Route History function on the Route Manager. The latter option is a Performance Member feature, although free members do have access to the route history for their earliest route created in the list.

 As to whether a Performance Membership is worth it for people whose goals are weight loss and overall fitness rather than a race, it certainly could be.  I find that having a training plan loaded into my log and having today's workout emailed to me or just listed in my training log increases my likelihood of actually training that day, whether I have a race coming up or not. There's a larger number of graphs available of your training data, as well as nutrition reports and graphs.