Just a couple of quick thoughts on the 7120. Got one for each of my kids. Amazon appstore runs great on these, and I've loaded a bunch of games and stories on them. My son is 9, so I put nook on it so he can read the wheel of time series, and downloaded a bunch of read along stories for my 4 year old princess.
My wife has an original galaxy tab, and while the kobys (of course) aren't as fast or smooth, they are great devices for the price and the kids love them! Plus, the wife is ecstatic just to have their grubby little paws off her GTab! lol!