I played with it on a server that I joined briefly (not their fault, they were awesome -- soil gravity was crashing my client).
It definitely has a lot to recommend it, but the rivers don't feel real. They have currents, which is super cool (though I think resource-intensive). However, I think they are all at sea level, which means that they're almost always at the bottom of a canyon. There's no sense of rivers running downhill. And when they run up against a geologic formation high enough, they cut through with a perfectly circular tunnel. Honestly, I'd guess that if the devs took inspiration from the mod, the uncanny tunnel shape is probably the easiest thing to fix. I'm pretty sure the big thing they're crunching on is integrating rivers with landscape elevation.