(This was not the car I drove, but it looks similar)
First of all, when I got in the Citroen C4 and closed the door I was surprised by the "tin can" sound. It made the door feel cheap and weak. The interior was full of hard plastic. I started the car and grabbed the gear stick. It felt wobbly. But when driving off I was surprised by the responsive petrol engine. Getting out on the highway the car accelerated okay, but there was some engine noise. I think the car was set up with gear ratios that makes the engine feel responsive, but at the same time it gets noisy. On the highway the car felt a bit unstable when going over 120 km/h. And the engine noise was massive. So it's definitely no highway cruiser.
It was an okay car, but after driving Saab for the last 8 years, I would never trade any of the Saab's I've owned with the Citroen C4. It feels very good to be back in my own Saab 9-5. I am a very happy owner. :)