I finally decided to compare the two for myself side by side on my own car. It's black and has no clear coat, so your mileage may vary. I took these pictures one day apart in the same place from the same angle with the same weather with the same camera so it's about as scientific as I'm going to get. I definitely prefer carnauba and since I'm going to wax my car every couple weeks regardless of what I'm using, durability isn't really an issue.
Anyhow, here are the pics:
I also have a larger (480k), higher res photo you can check out, but I was trying not be too obnoxious in the post.
High Res Version
Anyhow, here are the pics:

I also have a larger (480k), higher res photo you can check out, but I was trying not be too obnoxious in the post.
High Res Version