No mouse hook up, but the controller isn't bad. The system is very well thought out, given what is possible with the traditional control scheme.
That said, the learning curve is pretty significant. Just as depth is confusing in the gameplay, it's also confusing in the editor. I may have these reversed but I think, L1 and L2 change the thickness of the object (relative to screen depth) and R1 and R2 change the position of the object (relative to screen depth). Whenver you push one of those buttons the camera movves so you can kind of see, but it gets quite cluttered if you have a lot of things on the screen.
Other buttons and tools take a lot of learning too, but I have a feeling it will be quite smooth for those that take the time to get used to it.