After 2 days your "old" W215 will look like a classic...
I had a 2001 CL500 and just bought a 2007 CL500, the difference is astonishing in every aspect:
Much bigger presence, because of the size (disadvantage is that you cannot easily park at some places that you usually did with the 215, but I can live with this..)
Much higher ride comfort, ride noise is muuuuch lower, suspension is superior at all conditions and the engine is much more powerful and pleasant to drive.
Before the 215 I had a W140 during almost 10 years, and I can say that the 216 gives you the same powerful feeling of the W140, if you know what I mean...
Just go for it and you will not regret
But, don't take me wrong, the W215 is still better today than 95% of all cars in the world!