Chadd: Another couple of questions:

Is the banding effect equal on the 4 vertical faces? Or is it equal on opposing faces? Just wondering if it's dominant on one axis or the other.

The other question: is your heat bed "pre" or "post" stiffener upgrade? (The ribs underneath the bed that Colin added after the warping problem became really apparent).

I ask because when I look at the 24mm cubes I first printed, they don't show anything like the effects you're showing. BUT..., not too long ago, I went around and did a general tightening of things, in particular the belts and x-carriage, and ended up with some artifacts I didn't have before. I haven't tried reprinting a cube since "the tightening"..., but I wonder if it would show something similar to what you're seeing now...