Turned the B class in two months early and jumped on one of the Smart deal. One of the reason I did it was because I can waive the $595 return fee on the B and my tires are at exactly 3/32nd, there is no way they can make it till June 30th without needing to be replaced. Since the C350e sucked, the Smart is the only thing in the MB family that I can get. I have only done 50 miles on it, but so far so good. It's just a basic transportation that cost me nothing and I don't hate driving it like a compact. I think with the right expectation set, I am happy.
Sad to see the B go, it was a reliable car for us. We enjoy having it much and would recommend it. I did buy the fully loaded one for my wife, but she ended up not using many of the tech features as they all sucked (the dvd, the self parking, the parking sensors, the enhanced nav). The only thing my wife is going to miss is the keyless entry as the smart doesn't come with a Smart key or mobile app.