I agree the inside materials are still not where I would like them [same issue with my S500]. But with the EU recycling laws, I am not sure we will ever end up with much better. AUDI is the only one that seems to put together a good looking Euro interior.
As for the CLS, I just found out a bit back that it is based on the E Class chassis. That little S at the end tended to suggest otherwise.
When I was looking for my new car, the gray market dealer showroom floor had one of each and it looked like the same leg room in each so the next time I visited I brought my measuring stick. Leg and head room in the back and front only differed by 1/4 to 1/2 an inch between the CLS and E. Seating between the 2 was 4 in the CLS (due to these unpopular buckets in the back) and 5 in the E. Price difference between the 2 with basically all the same options on each) the CLS 350 was priced about 35,000 USD above the E280.