I think when I was researching, they have much improved the mechanism (QL-2) for clasping onto the rack and are far easier to adjust as you don't need tools like on the classics. I have the plus and they really are excellent.
They come in a nice matte finish rather than the glossy classic ones too.
You probably won't go wrong with either. Mark Beaumont cycled round the world with the classics and recommended them to me when I asked him, but I still opted for the plus.