I was spending some time comparing my options for world-gen and I finally noticed that there aren't any rivers in the ATG version. I really like the way beaches generate, how the mountains have crests, and how the biomes are spread across the map. I just wish I could row my boat around the rivers like I did in vanilla.

I'm pretty sure that the problem is how in minecraft you need a continuous stretch of flat land to make a basic river, to make rivers work in ATG someone would have to account for height changes every couple blocks with very few exceptions.