The Boxster/Cayman range has a reputation for being among the most balanced, rewarding sports cars available. Having replaced my '04 Boxster with an '08 Cayman S, I can confirm that they do not disappoint over the long term. Handling, braking, and general comfort and utility are all top notch. Only a relatively stiff ride and a bit more interior noise than one might want detract from the overall experience.
The enthusiast mags generally rate this as the best handling car under $100k, and having owned and driven a wide variety of sports and GT cars, I wouldn't disagree. Incredibly precise and communicative steering, minimal body roll, and plenty of grip. Probably the car's strongest asset - no nits to pick.
The Cayman continues Porsche's classic shape, but in a more voluptuous form.
The water cooled flat 6 makes the signature Porsche sound, and pulls smoothly to its' 7200 rpm redline. Low end torque is a bit lacking, but with an engine this smooth and eager to rev, that's a minor issue.
Fuel economy is reasonable relative to the car's performance - 20 mpg, plus or minus a couple depending on the balance of city versus highway driving.
Two cargo areas - one in the nose and one under the hatch. The front area is deep but not particularly wide, the rear is wide but shallow. Bottom line, groceries or a weekend trip are no bother, but if you're going to Home Depot, you make want a different vehicle.
Ride is stiff, particularly with the 19 inch rims. The price to be paid for the Cayman's incredible handling.
One of the few areas where the Cayman lacks. Noise levels at highway speeds are slightly elevated, and (along with the stiff ride) make the car a bit tiring on long drives.
Audio & nav systems
Even the optional Bose system is weak - imaging is OK, but clarity, particularly on the bass, is poor.
Warranty, maintenance cost
Stay away from the dealer - service prices are outrageous. Find a good independent mechanic.
Porsche reputation is legendary. While their recent foray into SUVs and sedans has diluted that image somewhat, their sports cars remain as satisfying as they come, and the Cayman, particularly in "S" form, is arguably the best that they have ever offered.