The 2014 Acura MDX has readily outsold all its competitors in the three-row luxury SUV category.

With sales up more than 68% so far this year, Acura is billing its MDX as the best-selling three-row luxury SUV ever. The redesign has clearly clicked with consumers, but the MDX has been a hot-seller ever since its introduction 15 years ago, topping all other three-row competitors every year since 2002.

That’s the good news for Acura, but there’s also plenty of bad. Despite introducing several new passenger cars in recent years, including its entry-level ILX and flagship RDX, Acura’s passenger cars simply aren’t cutting it with consumers.

So, despite the surge in sales of the brand’s big SUV, Acura’s overall volume slumped 18.6% in June, making it one of the few brands to report a decline as the U.S. car market continues its recovery.

“MDX is the clear benchmark in its class,” crowed the Acura Division’s General Manager Mike Accavitti, proclaiming that “Luxury car buyers have spoken.”

Now in its third generation, the MDX has won almost uniform raves from consumers and third-party experts, alike – it is, for example, one of only two vehicles in its class to achieve a five-star Overall Vehicle Score from the National Highway Traffic Safety Administration, as well as a Top Safety Pick+ rating from the Insurance Institute for Highway Safety.

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While not the biggest vehicle in its segment, the MDX was among the first three-row SUVs in any category. It boasts a roomy interior and plenty of cargo space, a well-appointed cabin, and plenty of other amenities – along with a competitive price. And it also doesn’t hurt that the overall SUV market has been booming in recent months, notes IHS Automotive analyst Stephanie Brinley.

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Whatever the reason, Acura sold 30,664 MDX utes during the first half of 2014, bringing its cumulative volume to 692,710 since it was launched in 2000. The luxury division of Honda Motor Co. anticipates topping the 700,000 mark well before the end of the year.

(The MDX has topped the luxury, three-row segment since 2002 – or so it claims. Buick, which is sometimes described as a luxury brand, other times as mainstream, outsold the MDX with its Enclave last year, 60,534 to 53,040.)

Unfortunately for Acura, the brand has only two other models in the positive category this year, and sales of the smaller RDX line are up a meager 0.7 since January – while demand plunged 13.4% in June. And while the flagship RLX is up 33.3% for the year to date, it suffered a sharp 54.1% decline in June.

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As for the entry-level ILX, despite Acura’s high hopes, it is off 22.1% for the year, and slipped 38.4% in June. Buyers last month purchased just 44 ILX Hybrids – which helps explain why the gas-electric model goes away for the 2015 model-year.

Acura has made a number of mistakes in recent years, analysts stress. It is phasing out the quirky ZDX, a coupe-style crossover that generated just three sales last month, and 56 since January.

“It was an answer to a question nobody asked,” said Brinley.

The real test will come later this year when the Honda subsidiary introduces the all-new TLX, a replacement for the sluggish TL sedan targeting the mid-range luxury market.

Accavitti described the new model as “critically important” during an interview several months ago, adding that “We have to start somewhere” to turn Acura around. “There’s nothing wrong with the brand,” he insisted, but acknowledged it has had some serious challenges in a hotly competitive luxury market.

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“The brand feels like it’s lost,” said analyst Brinley. “It hasn’t been able to connect with consumers.”

Acura is hoping it will do a better job connecting once it launches its reborn “halo car,” an all-new version of the 2-seat NSX sports car.  A production version is expected to be shown either late this year or in very early 2015. The supercar will be a showcase of the maker’s technological prowess, using a unique, three-motor hybrid system paired with a turbocharged V-6.

While the NSX isn’t expected to generate significant sales, Acura hopes it will focus attention on the brand and draw in buyers for a wide range of models, not just for a single, three-row SUV.