"Cute?" exclaimed an outraged Susan Sarandon in "Bull Durham." "Baby ducks are cute! I want to be exotic and mysterious!" Alas, the 2010 BMW 1 Series is none of the above. With its upswept rocker panels and top hat of a greenhouse, this entry-level BMW is aesthetically controversial, to put it kindly. What's not controversial, though, is its combination of scintillating swiftness and remarkable refinement, which clearly sets it apart from other sporty two-doors.

From the 1 Series' compact dimensions, one might reasonably assume that it's significantly lighter than its 3 Series brethren, with which it shares many mechanical components. Such is not the case: The curb weights are close enough to make the 1 more of a junior 3 than a throwback to the days of classic elemental BMWs like the 2002. No matter, though. The 3 is an excellent foundation to build on, and indeed, the 1 delivers generally 3 Series-esque handling and ride comfort, the exception being occasional impact harshness from the run-flat tires.

The 1 also shares the 3's inline-6 power plants: a 3.0-liter naturally aspirated unit and a twin-turbocharged version of similar displacement. Even the former is plenty spry in the 128i, yielding a 0-60-mph sprint of about 6 seconds flat, while the latter's 300 horsepower propels the 135i to 60 mph in the low-5-second range. These numbers alone should help smooth over any concerns about the 1 Series' elevated price, as should the preternatural smoothness of each engine's power delivery. The 1 Series is every bit a proper BMW from behind the wheel -- a sophisticated tool for discerning drivers.

Discerning drivers not finding the 1 Series quite to their liking will have only a few other alternative choices. The closest in mission statement is the Audi TT, which also offers a convertible body style (though unlike the coupe it only seats two) and sports-carlike performance. It's more stylish but not quite as fun to drive as the BMW. Other choices could include the less refined but plenty powerful Ford Mustang GT, the roomier but less nimble Infiniti G37 and the two-seat Nissan 370Z.You should also check out BMW's own 3 Series as it's a more pleasant car all around, particularly in convertible trim. But the step up to a 3 Series doesn't come cheap. If you're alright with its looks, the 2010 BMW 1 Series is a must-drive in this segment.

The 2010 BMW 1 Series is available as a compact coupe and a soft-top convertible. Both come in 128i and 135i trim levels.

Standard equipment on the 128i includes 17-inch alloy wheels, automatic headlights, cruise control, rain-sensing wipers, leatherette premium vinyl upholstery, a tilt-and-telescoping leather-wrapped steering wheel and a 10-speaker stereo with a CD player, HD radio and an auxiliary audio jack. All convertibles also come with a power-operated soft top and an upgraded climate control system. The 135i trim level comes with a more powerful engine, a sport-tuned suspension, 18-inch wheels and all the standard equipment of the 128i plus a sunroof, xenon headlights and automatic climate control.

Options on the 128i include a sunroof and a Sport package that features different 17-inch wheels, performance tires, the 135i's sport suspension and sport seats. The 135i Sport package includes the sport seats and an M Sport steering wheel. The Premium package adds auto-dimming interior and exterior mirrors, upgraded interior trim, mood lighting, BMW Assist, Bluetooth, leather upholstery, power front seats with driver memory and, on the 128i, a sunroof. Popular stand-alone options include active steering, keyless ignition/entry, a hard-drive-based navigation system with the iDrive controller, rear parking assist, an iPod interface, satellite radio and a premium audio system. Heated front seats are also available by themselves or via the Cold Weather package.

The 1 Series convertible's options list also includes a Moonlight Black soft top with shiny metallic fibers that produce a metallic silver appearance in sun- and moonlight. The convertible's optional leather upholstery also features BMW's exclusive sun-reflective treatment, which the company claims can lower the seat surface temperature by up to 20 degrees.

The rear-wheel-drive 2010 BMW 128i is powered by a 3.0-liter inline-6 that produces 230 hp and 200 pound-feet of torque. In performance testing, a manual-equipped 128i coupe sprinted from zero to 60 mph in 5.9 seconds. The 135i features a turbocharged 3.0-liter inline-6 that makes 300 hp and 300 lb-ft of torque. We pulled 0-60-mph times of 5.1 seconds for the coupe and 5.5 seconds for the convertible. A six-speed manual is the standard transmission on all trim levels, and a six-speed automatic with manual shift control is optional.

EPA fuel economy estimates for the manual-shift 128i coupe are 18 mpg city/28 mpg highway and 21 mpg combined, while the 135i coupe with the manual has 17/25/20 mpg ratings. Changing body styles and transmissions doesn't affect these figures much.

Antilock disc brakes (with brake drying and standby feature), traction and stability control and start-off assist for manual-equipped cars are all standard on the 2010 BMW 1 Series. Front-seat side airbags and full-length side curtain airbags are standard on the coupe; convertibles come equipped with front-seat side airbags that extend higher to protect occupants' heads. The convertible also features pop-up rollover hoops.

It'll take a real purpose-built sporting machine to outrun the 2010 BMW 1 Series on a winding road. Though some hard-core drivers might find that the car's handling isn't as rewarding as other BMWs when driven at the limit, the vast majority of owners will find that the precise and responsive steering, excellent body control and great outward visibility make the 1 Series a treat on curvy roads. The ride isn't as refined as in a 3 Series, either, but it's quite good relative to the 1 Series' rivals. You'll be hard-pressed to find a better combination of athleticism and compliance in this segment.

Even the base 128i's naturally aspirated inline-6 is a gem of an engine, gliding from idle to redline on a smooth wave of turbine-like power. The 135's twin-turbo inline-6 engine cranks the power knob to 11 while retaining every bit of that characteristic smoothness. Although this top-of-the-line powertrain gets most of the attention, the 128i is arguably more involving to drive because you actually have to think about what gear you're in; the 135i, conversely, packs such a wallop of torque that frequent downshifting isn't as necessary. But no matter which 1 Series you choose, you're in for a good time.

Read our BMW 135i Long-Term 20,000-Mile Test

The 1 Series' interior is generally competitive with its rivals in terms of materials quality, but hard plastics are more prevalent here than in the 3 Series, leaving no doubt about the 1 Series' entry-level status. However, most controls are straight out of the standard BMW playbook and easy to use. The base seats are remarkably lacking in support given this car's performance potential; we strongly recommend anteing up for the Sport package and its superb manually adjustable sport seats. The convertible's optional sun-reflective leather seating adds a welcome touch of luxury.

If you check the box for the optional hard-drive-based navigation system, the infamous iDrive interface comes with it. Don't fret, though: BMW improved it toward the end of last year with more physical buttons and a much-improved menu structure. In fact, the reinvented iDrive has shot up to the top of our rankings for such interfaces.

Although the 1 Series is technically a four-seater, the rear seats are significantly more cramped than in the 3 Series coupe -- they're best left to those of smaller stature or cargo. The coupe's decent-sized trunk holds 13 cubic feet of luggage; in the convertible, there are 8.5 cubes left over when the top is stowed.