Seems that I'm another narcissus. I'll own up to videoing myself, hey I've even done it while I've been shooting
If you have a particular element of the shot in mind then I've found it to be useful, but I tend to find the viewing angle too small for detail at the same time as a global view. If you want a good view of, say your loose, then you need a cameraperson. Similarly, if you want a view from the back you'll get more useable video if someone aims the camera for you.
What is useful is a digital video & a PC to play it back, slow down etc. The frustration then is that your loose can quite easily fit into 1/25 of a second (the frame rate of the video) & you need a lot of shots to get a feel for what's actually happening.
One more thought - if you do this as a "you scratch my back I'll scratch yours" then you have to be prepared to listen to the coaching from your partner
