I guess they are all basically the same, though different enough to allow relief by one of them should another fail. That is what happened to me. No relief from rhinocort, flonase, nasacort. Nasonex finally helped. It is worth the exercise.
The nasal sprays are all corticosteroids with different medications in them. I put the links to webmd.com if you would like to see the differences. I only responded to Flonase and have been using it for the last 10 or so years.