Very recently I had a chance to (very briefly) try a friend's Citroen C1...but it was enough.
It felt more like a van to sit in, and the clutch felt a lot heavier than my GD Jazz does. It was a 1.0 litre (three cylinders I think), but sounded more like a diesel when started. I know it's in the city car segment of the market, but I was surprised at the lack of refinement compared to the Jazz. Getting in and out was more of an effort too, as it's lower than the Jazz.
The good thing about trying out other cars like this, is that it really makes you appreciate anew the one you use yourself. In this case, I sat back in my Jazz later with some satisfaction!