Kia Motors' (KIMTF) new version of its Optima is arriving at dealers now, and after extensive testing of this car, we can conclude that it's a top pick in its class.

But before we get into the details of our review, it's worth it to stop for a moment and marvel at just how far Kia Motors has come in the U.S. Back in 2001, the company ranked dead last in the J.D. Power quality survey of the U.S. car market. Fourteen years later, the South Korean automaker has advanced all the way to the No. 2 spot, behind only Porsche. Kia is on track to sell 625,000 in the U.S. in 2015. A generation ago, it sold none. Kia is now the eighth largest brand in the U.S. and will sell approximately 25 times as many cars in the U.S. as Tesla will this year.

So how did Kia Motors do it? For one, the company shifted a lot of production to the U.S., where Kia now builds approximately 40% of the cars it sells here.

One such model is the Optima, which has become Kia's best seller in the U.S. In October 2015, Kia sold 14,381 Optimas in the U.S, and it's on track to sell approximately 160,000 for the full year.

Kia is of course the sister company to Hyundai (HYMLF) , which still owns a significant stake in Kia Motors. And Kia's Optima has a sister car in Hyundai's Sonata, which sold 16,071 in the U.S. in October and is on track to exceed 205,000 cars for the year. Therefore, on a combined basis, the Kia Optima and the Hyundai Sonata are on track for sales of 365,000 in the U.S. in 2015, a significant chunk of sales in the midsize sedan market. So how do these two cars differ from each other?

The exteriors of the cars are very different. The Hyundai Sonata looks extremely bland and anonymous. This is the car you want if you want absolutely nobody to remember having seen it. I'm not saying it's ugly; I'm saying that you'll forget about it in a parking lot.

In contrast, the Kia Optima has an extroverted, expressive styling. I think most people will like it and prefer it over the Sonata. That doesn't mean it's a masterpiece, but I think it's reasonably good and isn't boring.

On the inside, few things differ between these two cars, but the few things that do, seem to be all in the Kia Optima's favor. First, the Kia steering wheel is richer. Second, you can get a more upscale set of interior trims, including the seat leather.

Basically, you are able to option the Kia Optima to make the interior look like a car that's at least one class higher than the usual bland midsize sedans. The fully tricked-out all-new 2016 Kia Optima interior could almost get confused with an Audi A4 or BMW 5-series car. It is very tasteful and pleasing to the eye and touch.

Kia made a big deal about the front seats. Although the headrests were supremely soft and pleasant, I actually didn't find the seat bottoms to be all that comfortable. After four hours behind the wheel, I started thinking they were below average.

The design of the instrument panel and center console are as close to flawless as any car comes. The Kia Optima has every millimeter just right. There is zero confusion, all the features are there, and the storage cubbies are ideal for keys, phones, coffee cups and more.

Android Auto is standard on most trim levels, and this system will be upgraded via software to also include Apple CarPlay in the next few months. It worked flawlessly, and is a huge selling point against those midsize sedans that don't have this. I'm looking at you, Toyota Camry, Nissan Altima and Subaru Legacy.

What about the driving experience? Honestly, not a lot to say about it. It's very neutral and should not be surprising to anyone. It's competitive with some of the best in the class, which means that anyone who hasn't driven one of these cars in the last two years will be pleasantly surprised.

I drove two of the three engine options -- the more powerful 2.0 liter turbo with traditional 6-speed automatic, and the 1.6 liter turbo with the 7-speed DCT (dual clutch automatic transmission). Maybe it was just the unit I drove, but I thought the 2.0 liter turbo was a little glitchy when accelerating from zero speed.

The 1.6 liter turbo with DCT, on the other hand, was razor-sharp in its response and felt a lot more joyful in getting up to speed. It was a little noisier as it revved higher, but not unpleasantly so. It also gives better fuel economy -- 39 MPG highway instead of 32 MPG.

The downside with the 1.6 liter turbo with DCT is that you can't get it equipped to the same level as the 2.0 liter turbo -- the so-called SX-L trim which has the most luxurious interior and all other upgrades. In fact, if I were Kia, I would consolidate all three engines for this car into one -- the 1.6 liter turbo with DCT, and make it available with all trims.

The cheapest 2016 Kia Optima starts at $22,665, but with a reasonable level equipment package you'll be paying right around $30,000. The range-topping SX-L with 2.0 liter turbo is $36,615.

These prices are within $1,000 of the main midsize competitors. As it stands right now, of the cars that are in dealerships this week, I rank the all-new 2016 Kia Optima as an equal among the top four, together with its sister Hyundai Sonata, Volkswagen Passat and Honda Accord. I drove them all recently, and these cars are extremely similar on most counts.

I find that the Toyota Camry, Ford Fusion, Subaru Legacy and the 2015 Nissan Altima fall short on features. In particular, they lack Android Auto and Apple CarPlay. For that reason, I cannot recommend them against the four current class leaders.

The refreshed 2016 Nissan Altima launches this week, but I have not driven it yet. The all-new GM Chevrolet Malibu is also just around the corner, and will have not only Apple CarPlay and Android Auto, but also 4G LTE and WiFi hotspot as standard. For that reason, it could be a strong contender to be the class-leading car -- but I have not driven it yet.

Lastly, while the Hyundai Sonata has both a hybrid and a plug-in hybrid variant, the Kia Optima versions of those will not launch until a few months from now. They will broaden the appeal of the Kia Optima even further.

In summary, the all-new 2016 Kia Optima is terrific. While the engine and trim combinations are not ideal, it's close enough where I put it on par with a couple of the other midsize sedan leaders. It's a top recommendation in this class.

This article is commentary by an independent contributor. At the time of submitting this article for publication, the author was short TSLA and long AAPL and GOOG. Kia paid for airfare, lodging and meals at a product launch event for the 2016 Kia Optima.