I have been filmed running and have attended clinics on Pose. Worth it mainly to understand elements that contribute to efficient running. Some people can just read about it and apply it to themselves; others will benefit more from an actual clinic.

The key thing to remember is that if you decide you need to make changes to your running form, is that you do it SLOWLY. I have seen runners try to change things too quickly and this can lead to injury.

Personally, the biggest thing I've learned (and practice regularly) is to keep a high cadence--90-95 right foot (left if you're a lefty) strikes per minute. Other than that, I really haven't tried to change my running form. The second biggest thing I've learned (well, I intrinsically knew this), is that the lighter you are, the easier it is to run, and to run a lot. Third--wear the right shoes and learn how many miles you can safely get out of them. It varies a lot. I'm really light, and I wear lightweight trainers, but I can only get about 250 miles out of them. That's just the way it is. If I use them longer than that, I notice things beginning to hurt.

Whether you need to attend a running clinic to find this out or not is your choice--there are other subtler elements of running form that can be played with--the important thing is to learn what are the biggest contributors to you running fast and healthy.