[crazy.neo]

Rockchips are better than Actions, no question. the reson Actions are so popular is because they are cheap, and easy to produce. That makes it suitable to equip all kinds of clones. Rockchip, on the other hand, tends to be more original. It's faster and generally offers more functions, and FPS's in video function. Also, the amount of formats supported is usually extended comparing to a Actions chipset.
So, it's not really a question of which one is better, it's a question of how much you are willing to spend. I'd wait a while before buying a new one, because new Actions and Rockchip chipsets with AMAZING speeds and capabilities are coming out next year (some enhanced Actions are already out, actually).