I've owned some very nice vehicles (Porsche, BMW, etc) but this is without a doubt the finest sedan I have ever owned or even ridden in. Smooth, quiet, comfortable with excellent handling and almost shocking acceleration. Unlike most cars (especially hybrids), the EPA rating is accurate. Took it on a long trip recently and got 38MPG with the cruise set at 75. I see no reason at all to even consider an E350. Ultra low sulphur diesel is still a bit hard to find but getting better every week. What's in the tanks at most gas stations is usually ULSD but most stations haven't been certified yet. Luckily, I only have to look for fuel about once or twice a month.
Beautiful workmanship. Seat comfort. Fold down rear seat. Multi-MP3 disk player. Razr specific Bluetooth adapter. The diesel engine is the real star - just amazing. You never get the feeling it's ever straining.
The transmission definitely needs work. Shifts smooth as silk some days but not others. Wish it had XM instead of Sirius