I used to have a Smart Car. I used to well knock them as well until I had a play in one. Running costs they are dead cheap. It used to cost me £12.00 to fill it up and that would be good for a full week+ of commuting from Portsmouth to Farnham. I used to get about 55mpg out of it, and that's driving it flat out everywhere. If you drove it with a light foot then you can see much more than that, 65+, I'd never seen that much though.
With the limiter in place they will sit at 83mph in sixth gear doing about 1.1k rpm, very ecconomical cars. The switchable 6 speed sequential box can be a bit funny if you drive it full auto as it can get a bit confused/slow through the gear change, drive it in semi-auto sequential mode and get used to it and you can get the thing going pretty well. Left hand drive isn't really an issue, it doesn't feel like you're driving a left hooker to be honest.
Getting it chipped makes quite a bit of difference to the auto gerachange makes it alot smoother, as well as removing the limiter at the same time. Bailey do a dumpvalve kit on it which always used to put a smile on my face. All the little chavvy kids round my way used to laugh at the car until they heard the dump valve, then they were all like 'mister has that got a turbo' etc...
It's also suprising how much you can get in them. I remember seeing the face of a Volvo driver just drop when I came out of B&Q with a brand new petrol mower, all boxed up. He looked at me then eyed up the car and you could see him thinking 'no chance pal'. That was when I just opened up the passenger door and slotted the thing into the cockpit sideways, the look on his face was priceless. When you open the doors you're opening up pretty much the entire side of the car.
Options wise they usually come with ABS, twin airbags, semi-auto sequential 6 speed box, Air con, CD etc... I was quite impressed with the amount of kit that it had with it when you look at the price and size of the thing.