Well... there are some differences ;) The first one I used was Turtle Wax, can't remember what they called it. That stuff was awesome! It had a black dye in the coating, was really easy to apply and lasted a long time. For some reason they removed that product from the market ;(
Then I tried Optimum's Tire Coating. It was ok but working it a little made it felt like you were spreading a light glue / or tacky syrup. I really did not like the application but it did last a long time so it did it's job.
The one I settled on was McKee's 37 Tire coating and I have been happy with it so far.
Thanks to The Guz I was made aware of a new formulation. So I ordered a bottle today. Curious to see if it will be better ;)