Neo died when they created the NeoCash whatsit. And Res has much more active, interactive staff that you can get to know and speak to when you have a problem. Another Neo downside, you can CREATE THE PETS. Res is more realistic, seeing how you have to first find the egg, then incubate it, THEN hatch it. And still you have no control over what color it's hatched.
Neopets is also too commercial. Like, literally. They have TV ads that come on on all of my channels all of the time. They also have collectible plushies and cards that always get on my nerves, since we're broke and don't want to pay to enjoy the full Neo experience. And they're EVERYWHERE.
Res is kind of cool since it's not a site that everyone knows about. It's more, you know, on the sidelines. And there's a lot more user interaction, witht he SB and all. Another neat feature is the staff being around to monitor conversations and such, instead of having such an incredibly strict computerized monitor.
So yeah.