A another well written, thorough review of the JCW MINI Cooper S – here's an excerpt:

Mini fanaticism coursed through our offices during the year a Cooper S lived in the Edmunds.com long-term fleet, and some of us have never recovered. I include myself in this group. And just when I thought I couldn't wait another day for my next fix of this BMW-engineered hatchback, a dark blue Cooper S with the dealer-installed John Cooper Works package showed up in the parking garage. It was sure to be a good weekend.

Pulling up the steep incline to exit the company garage, the extra low-end torque was immediately noticeable. The Cooper S settled easily into first gear, and even the distracted driver would be hard-pressed to inadvertently slip the clutch. If you live in San Francisco, the Works upgrades will spare you a fair amount of frustration and clutch wear.

As we continued on in city traffic, we enjoyed the subtle change in the car's behavior. Although the Works package is ostensibly geared toward enthusiasts, the average driver will appreciate the enhanced engine's more tractable personality. The car is quicker off the line from stoplights and able to catch more of the breaks when merging and passing in freeway traffic. When we took a trip up Interstate 5's Grapevine stretch, known for its switchbacks and rapid elevation changes, our Mini easily held sixth gear all the way up at an 80-mph pace. In contrast, our stock long-term Cooper S needed regular downshifts to fifth to maintain speed on this route.

By 3,000 rpm, our John Cooper Works car felt downright potent. And with the new exhaust system providing a slight variation on the standard Cooper S soundtrack, there was all-new fun to be had in taking it to redline.

Our test car got through the cones at an average speed of 67.7 mph, and anytime you're closing in on 70, you know you've got something special. Karl noted afterward, “Our test car felt a lot like a go-kart with basically no body lean to speak of (typical Mini), but the increased power helps over the stock S when exiting the cones.”

One other thing we noticed about our test car's driving dynamics was the slightly less punishing ride quality over ruts and expansion joints compared to that of our long-term Cooper S. Since both cars wore 17-inch run-flat tires, we can only speculate that this car's optional leather seats provided a bit more cushioning for our auto journalist glutes. Besides that, the black-and-blue hides were a nice complement to the Indi Blue exterior paint. Yet, the leather didn't feel all that high in quality, so we don't recommend that you spend $1,300 to get it.

…It's a one-time deal – no need to add anything else unless you want to. Secondly, unlike other aftermarket modifications, the Works is fully backed by the factory warranty. And since Mini dealers do the installation, you're reasonably assured that it will be done properly. So if you're a) devoted to the Cooper S in your garage, b) have extra money to spend on performance and c) don't want to get too deep in the aftermarket, you may want to go with the Works. Us? We'll take a stripped Cooper S and pocket the difference.

It's worth noting that the slightly more compliant ride that Edmunds commented on is most likely the result of the revised shocks that MINI introduced last May (to much negative opinion from current owners I might add). Sounds like the change was indeed an improvement in Edmunds eyes.

You can read the entire article here.