The only Mercedes I'd driven until recently was a 1986 260E sedan. I drove it in about 2002 and I was shocked at how powerful, comfortable and solid it was even at that age. It was like driving a ship. One word that could sum it up was HEFT! What was strange was I always swore I would never own a Mercedes as they never appealed, but the 260E was a riot to drive.
However, since then I've driven the new C220 CDi Avantgarde and was really impressed by that. I drove all over France and it never made me tired. I also loved the looks of the thing. The new C-Class looks superb with the large sports merc tri-star in the grille, rather than perched on the bonnet.
I've always hated the E-Class since it got the 4 oval lamps and hoped that Mercedes would bring the style of the new C to the E. This new one looks far more imposing and sporting, which I presume was the intention. If the production model has half of the grit of this concept, it'll be a roaring success. Lets hope they can get the proportions of the sedan right.