I feel the urge to post something since 190D threads are so rare...
I have a 190D-2.2 5-speed. On the past 5 tanks of fuel, I've gotten between 40.3 mpg and 41.5 mpg in mixed city/highway driving (at 65mph). At 70-75mph, the car gets around 38-39mpg. So, fuel economy is super-fabulous - you would cut your fuel costs in half if you bought one of these cars! With the manual transmission, acceleration is adequate (the automatic is noticeably slower), and on the highway, the car can maintain it's speed up moderate hills without downshifting.
However, if you need to drive 80+ on a regular basis, I don't think this is the right car to choose. It's tough to get the car over 90 (and it's probably not that good for the car). Maybe the 2.5 is better; I can't say because I've never driven one...
According to
www.fueleconomy.gov, the 2.5 gets 2mpg lower fuel economy than the 2.2, and the automatic gets 4-5mpg less than the manual on the highway.