The arrival of the Porsche Cayman S confused many people. Porsche believed they had identified a niche between the Boxster and the 911, whereas logic dictates that the soft-top version should be the more expensive.

When the Cayman S first arrived in late 2005, it debuted the company’s new 295bhp 3.4-litre flat-six and, at this point, we thought we understood what Porsche were trying to do. The Cayman, then, was a harder, more powerful, tighter-focused version of the Boxster, and that performance benefit justified the increased price.

Our reasoning fell apart, however, when Porsche replaced the Boxster S 3.2-litre engine with the Cayman S’s 3.4. And introduced a non-S Cayman 2.7.

With identical power and performance figures, what exactly do you get for £4,000 extra?

Of course, there’s a difference in the styling. At the front, the Cayman sees subtle differentiation with round fog-lights and titanium-coloured lower bumper strips.

But the big news is the metal roof. The roof-line now sweeps gradually towards the rear of the car, removing much of the separate rear deck that formed the basis for the push-me-pull-you criticism levelled at the Boxster.

It can look a little clumsy from some angles, notably around the rear three-quarter, but the beautifully sculpted curvy rear flanks bring a style all of their own. The electrically-operated rear spoiler is a curved affair, too, and forms a deliberate lip when in the down position rather than hiding away completely.

The rear window and deck now forms what is effectively the first Porsche hatchback, with a maximum 260 litres available in the rear in addition to the 150 litres at the front, in common with the Boxster.

With a solid roof, the Cayman automatically benefits from a stronger, more rigid chassis, but Porsche took things one step further by stiffening the springs, dampers and anti-roll bars.

These changes lend the car a more tightly focused feel, with greater cornering confidence and a more direct steering action that further enhances feedback.

While this re-purposing of the chassis set up does improve raw handling – Porsche is keen to point to the Cayman’s 8:20 lap-time of the Nürburgring’s northern circuit – on British roads it can prove overly firm.

Indeed, under braking on bumpy roads, the front end can skip over depressions, with the resultant loss of grip leading to an undesired change of direction if this happens mid-corner.

Oddly, this front-end bobbing sensation is something the Cayman has in common with the 911.

Performance figures are identical to the Boxster now they share engines: 0-62mph in 6.1 and 5.4 seconds for the 2.7 and 3.4-litre models respectively. Top speeds are 160mph for the 2.7, but 171mph for the 3.4-litre Cayman compared to 169mph for the Boxster S, no doubt attributable to improved aerodynamics.

Inside, it’s largely identical to the Boxster, although the re-profiled side windows improve visibility at junctions, and the engine note takes on a deeper character now that it’s enclosed within the cabin.

While there’s no arguing with the improvements in the Cayman’s chassis for track work, we find ourselves preferring the Boxster’s softer set-up for use on British roads.

So it’s a more focused Boxster, then?

We think this is the easiest way to look at it. Most convertibles are a development of their hard-top brethren. For the Cayman, however, it’s the other way around. And, rather than price their new model on features and specification, Porsche have set the price based on the handling performance envelope.

To prove the point, take a standard Boxster S and add the optional hard-top and Sportdesign package (front and rear aprons, sill extensions, revised rear spoiler) and you’ll have exceeded the Cayman S list price even before adding niceties such as metallic paint.

The true fly in the ointment, though, is the 911. Porsche has a pathological fear of treading on the 911’s toes. The Cayman chassis can clearly handle more power, and could really use a limited-slip rear differential – even without these things, the Cayman can beat its bigger brother around many circuits.  To our mind, a light-weight Cayman RS would top the range perfectly. It would make sense of the stiffer chassis, and would provide a clear raison d’être over the Boxster.

While the Cayman is undoubtedly the best-handling coupe on the market today, for our money we’d still elect to save ourselves £4,000, gain the option of open-air motoring, and savour the Boxster’s more supple suspension set-up.

Probably the best-handling coupe on the market today. We’d still choose a Boxster S over the Cayman – not just because of the £4,000 saving, but because the Cayman’s stiffer front-end can be a little over-firm for British roads. A Cayman RS would probably change our minds, though.
Our verdict: Our verdict: 4.5 stars out of 5