Not a popular opinion, but these are my thoughts...
They're nice little cars, as reliable as one would expect from a modern car and they seem to tolerate the years pertty well, but.......
With the brand dropped in North America, there are going to be longer and longer delays in getting parts and more parts will become NLA as the years go by. This can be a deal breaker for a car you need to rely on. All cars break down eventually, it's not a criticism of the Smart, but parts from the bigger players are more readilly available locally and there are more 3rd party manufacturers to support them for longer due to the larger number of vehicles on the road...
Plus keep in mind that a 2009 is 11 years old now, while that's not much for a modern car, it is coming up on the age where one can start to expect increased failure of some parts. You might get lucky and go years without a single failure or you might need to replace some of the more common items right away.
I think they're great as a second car, they're a blast to tinker on and in my limited experience they're reliable, but if my livelihood depended on a car being available for use, I don't know I would recommend a Smart for the aforementioned reasons. Again, it's not a knock on the car, but on the availability of parts in a pinch. If you can afford to let a car sit for a week or so while it's repaired, then go for it! They are fun to drive.