Tablets are Better

They are more expensive, but the good far outweighs the bad.

I have a 6-year old and an8 1/2- year granddaughters who share an iPad. Since you can set some parental controls, I don't worry about what they're getting into. The iPad has already helped their communication skills (they email all their grandparents) and it has opened up an new real of fun learning tools besides being able to read books they like over and over.

I don't have any experience with the Android tablets, but I know people who have them, and the options seem to be about the same and the price isn't as prohibitive as the iPad. Regardless of which one you choose, I think of it as an investment in their future.