The "Real Grade" line of Gundam models has been out a while now. This one being the first. It's small, so it doesn't take up much shelf space, but they're almost as detailed as a Perfect Grade kit. Many people don't like them that much because to get the detail this nice at this small size makes it a little more finicky and fragile than the standard HG and MG kits. I personally don't mind since I don't pose my Gunpla that much.
The RX-78-2 is the Granddaddy of all Gundams. It's the one that started it all. This kit was pretty simple as far as RG goes. I bought some aftermerket decals since all RG kits still come with the horrible stickers, which go straight to the garbage. Not much to say about the build really. It looks nice and it poses nice.