The new design design uses on axis mirrors to image the photomask onto the wafer, and on axis mirror systems are far easier to design and fabricate compared to zig zag (off axis) systems. I've never designed an EUV system, and I guess that Shintake's team had to solve some materials or optical coating technology issues that allowed them to consider the simpler on axis design. Having worked on zig zag and on axis designs in the IR and VIS range, I can say that Shintake's design will be much (orders of magnitude?) easier to align and assemble.