I am liking the
new (to me apparently, I see 5 does this as well, but never noticed it) ability to turn on sublayes in a detail when the parent layer is turned off for that detail. A couple of notes, if I have a layer that is currently on for a detail, and I move it to be a child of a layer that is off for the detail, it seems it per detail visibility should be inherited from the parent.
Any chance of bringing back the ability to have layers off in model space but on in details? That was pretty handy (all except the inability to select or do anything with a layer in that state).
I also like the new layer dialog UI, it makes it easier to see what is a child of what. I might suggest though perhaps a bit more indentation, or lines that might make it even a bit more clear?