Though only slightly longer, wider and taller than the Xantia the new model boasts excellent 'stretching' space and sufficient head, shoulder and elbow room to set it apart from rivals.
Though it was probably inspired by the smash-hit MPV concept, the quest to provide greater interior space is becoming increasingly important in the keenly-competitive business car market as pressure of work prompts more executives to spend more time on the move.
After 6,000 miles, the C5 is proving to be manna from heaven when it comes to soothing the negative effects of long stints behind the wheel. It's one of that elite group of cars that can be driven for hours on end and still leave its driver feeling fresh.
Our Exclusive 2.2 HDi version lives up to its name by cosseting its occupants as an ingenious computer-controlled hydraulic suspension system called Hydractive 3 soaks up the bumps.
It rides level irrespective of load, is soft or firm depending on how the car is being driven, and is even smart enough to lower itself at speed to improve aerodynamics and fuel economy.
As well as having all that space, technology that's useful rather than gimmicky really does help ease the strain of high-mileage motoring.
Drive through a tunnel and the headlamps come on automatically. The windscreen wipers sweep into action as soon as it rains and the air conditioning system reacts to the strength of the sun and raises the temperature slightly at night.
Added to satellite navigation, this level of gadgetry is a boon and reinforces the claim that the C5 is the most technically advanced Citroen yet.
Adventurous without being quirky, our example is proving to be a refined all-rounder, with only an intermittent squeak from the steering wheel to disturb travel in the Club-class manner.