After my C2 VTS I wanted something that was roomier, had better mpg, lower emissions and better spec. I also wanted it to look nice, but still be fun to drive. Having looked at many other medium sized cars, my choice was between either an Astra 1.9CDTi Sports Hatch and the C4 VTS HDi. I chose the C4 as it was slightly cheaper, better equipped, as well built, but crucially for me had a smoother and quieter diesel. To be fair to the Astra though, the C4 did feel a fair bit slower.
The first 3000 miles of owning the C4 has seen an average mpg of 40 around town, and 60 mpg can be reached at 70 mph whilst in 6th gear. It's worth noting at this point that at 70 mph the C2 VTS was pulling 4000 revs whilst the C4 VTS is just under 2000 - it's much quieter!!!
The C4 is good to drive with light steering, good handling, although I have driven a petrol version and can confirm the diesel understeers a little more, presumably due to the heavier engine.
Performance is good; initial acceleration is what you'd except of a diesel, but above 30 mph the engine can stretch its legs better and shows excellent responsiveness as well as acceleration - it has LOTS of torque! I'm a bit of a petrol head, but even I had to admit the engine even sounds good when you put your foot down; very deep, and when warmed up, it's even pretty quiet at idle.
Inside the car is very comfortable with leather/alcantara seats, dual zone air con, 7 disc CD player, laminated side glass etc i.e. all the goodies. The driving position is excellent and can be altered to suite all comers. Visibility is good at the front, but the coupe shape limits rear visibility - I am glad parking sensors are fitted. Talking of visibility, the mirrors might look aesthetically pleasing, but are fitted too far back on the doors to be 100% useful.
The only extra my C4 has is the Citroen sport spoiler as fitted to all petrol VTS's - curiously the diesel does not get this, but in my opinion it makes all the difference.
To sum up, I am very happy with my C4. I'll be the first to admit that if fuel costs and emissions were not a concern, I'd go for the 180 bhp petrol engine. In the diesel's defence, it's only £500 more, has 138bhp and substantially more torque, and sounds much better than the older generation of engines fitted until recently. If the fuel economy of the petrol VTS is what my dealer tells me (about 25 mpg around town), then the diesel easily beats it whilst being only 1.5 seconds to 60 slower, and I'd bet above this it's quicker. Furthermore, the road tax is only £115 a year and the insurance 6 groups lower. Bit of a bargain eh!