I personally have both of those tablets. I prefer the CTH-480 because the active area on the Gaomon has a little too much friction for my liking. This could easily be solved by getting a tablet cover for it.
I really like the pen for the Gaomon but again, the friction gets me. If you can find a CTH-480 for a decent price, I'd take it. I now own two CTH-480'S because the second one I got for $40USD which is a lot cheaper than buying a replacement pen if something happens to one of them.