Dave-
Not that I fully understand the technical specs, but this looks in line with others that I've seen.
I've not played through the Art Z, but I did a side-by-side-by-side-by-side comparison of my F1-X (pre-EQ), the Radial JDI (passive), the Radial J48 (active), and a Raven Labs DI. The winner was the F1-X. A very close second was the Radial JDI. Distant third was the J48 and then the Raven Labs. All were better than the standard DI's you typically see. I've also played through Rolls, Horizon, Behringer, and Whirlwind. They're nothing to write home about.
I have played through an Avalon U5 and was not impressed with the sound. It was too, ummm, sweet for my taste.
If you're looking to spend a bit of money on a really good DI (in excess of $200), take a look at the Little Labs Multi-Z. I've been told it's what Jimmy Johnson uses. The Grace Labs gear also gets high marks from what I've read.
Good luck finding the right one for you.
C-Ya.........wayne