As most of my sheltie friends' shelties are nimble and quick and do agility, our sheltie girl is only good at having her daily morning swing with her dad or chasing the kitties which are sitting on the walls.
Agility wise... you can forget about it!
You want a proof? There you are.
Somehow, the music on the video made it unable to be played on certain sites, so here is the link if you are unable to watch it: