The CLS is stunning, the local MB dealer is selling them like hot cakes to.
The new S looks ok, in black if looks sick from the front and pretty decent from the side. Silver isn't the best color for it. The rear view is a bit generic for a $100k car. The interior is extremly nice and MB has brought the quality back up. The interior in the new S is put together just as well as my W126's, and much better in some areas.
The W126 and the W140 look awkward from certain angles, nothing is perfect.