We decided to check them out even though neither of us are particularly impressed with the design - prefer the E350.
In any event, we didn't do a full on test because traffic was a bit of a mess.
We found the interior to be much nicer than our 328i. Dash display (gauges, radio, nav screen, etc.) much nicer - sharper and brighter. The car was much quieter than our diesel - oops I meant our gas powered car. The ride was smoother as well. Oh, and it comes with RFT's so no spare - salesman was kind of funny when he saw the expression on my face and proceeded to say most buyers have no interest in changing a flat (like that makes it OK?)
One thing they blew it on IMO is the turn signal setup. It has the "three flashes" setup BUT, if you push the stalk to the full detent spot, you can't lightly touch it to cancel - you actually have to push it in the opposite direction - first world problem. The outside mirrors automatically fold which is nice. I'm sure there are other plus/minus features but we didn't want to spend a lot of time - pursuing first impression.
Now, when it came to driving it, NEVER, and I do mean NEVER, pull up in a 328i and then drive the E300 for comparison! While the MBZ is smooth, it just doesn't have the "snap" the BMW has - not by a LONG shot. I had to put it in sport plus to get any type of "performance" feel at all. IMO, the BMW comfort mode is actually better than the MBZ in this little test.
Rats! I forgot to check to see if it has a dipstick.
All of this info is FWIW...