I'm surprised darkhorse's Brembo Max's warped but you can't beat personal experience of a product.
I don't know if this helps but here's some pics of ATE Power Discs old and new
I clocked them up and the run out was around 30 microns so didn't try to skim them on the lathe. It can only be felt at speeds below 10mph with v light braking and went through the mot fine. I do prefer the elliptical grooves on the powerdiscs tho