The second one was a very quick generation and it's just the default Wilbur renderer. I couldn't go quite as heavy-handed on the erosion and still ensure that the rivers end up in the right place. The river network in the lower right is physically impossible and if you look closely at the second image, you'll see that even though rivers are following the specified channels, there are a few breaks where the flow agents had to switch directions get be able to follow their prime directive of "go downhill". Pushing more erosion would likely have resulted in the elimination of some channels as happened in the first one.