I haven't done a park run yet, although I'm intending to get down to Endcliffe Park in Sheffield and run one there in the near future, I think they are all 5ks.

For established runners they seem to be a good way of varying the routine, maybe utilising them as an additional threshold (or whatever) session. That seems to be the feedback I've heard, and that is how I'll be approaching it.

For newer runners, they seem to be providing a useful and convenient entry point into racing and the notion of running 'en-mass'. We've certainly had a couple of new runners at Porter Valley that have done the park runs, got the bug and now want to take things to the next level, as in start running with other people, vary their training and start running other and more varied races. A couple of them have even expressed an interest in venturing out onto the fells.

I think on that basis they are a good thing.