Just looking at the website, I have these thoughts:
1. The fork has an alloy steerer, so it theoretically loses a bit of the carbon benefit.
2. The tubes appear to be pretty simply round -- many bike brands claim that custom shaped tubes tune the feel of their aluminum frames.
3. The fact that a cable hanger is optional seems weird. What fills that space if you don't have one? Isn't that plate structurally part of the dropout?
4. The screws they're using to secure the eccentric bottom bracket seem kind of odd. You can turn pretty much any frame with a BB30/PF30 bottom bracket into a singlespeed with an eccentric bottom bracket from Beer Components or Problems Solvers. These both use screws through the bottom bracket face to hold it in place once you have it rotated where you want it. The State EBB looks like it would rely on lining up with screw holes, which would make the rotation angles stepped rather than continuous.