A decade ago, HTC was known primarily for making phones with other companies’ names on them, though some were quite noteworthy. These included the T-Mobile G1, the first Android phone launched in the U.S. Today HTC is a well-known smartphone brand whose models earn admirable scores in our Ratings. And if my impressions of its latest flagship, the HTC 10, are correct, that will continue.

The phone, which measures 5.75 x 2.8 x 0.4 inches, is an aluminum unibody wrapped around in a brilliant, 5.2-inch quad-HD display that promises 564 pixels per inch of resolution. 

While HTC doesn't list any particular spec for withstanding physical abuse, the company does claim it subjected the HTC 10 “to over 168 hours of extreme temperature tests, ranging from a freezing -20°C to a scorching 60°C; and over 10,000 drop, bend, scratch and corrosion tests.” The phone felt solid in my hand, and the curved, chamfered back made it relatively comfortable to hold.

The rear camera has a 12-megapixel sensor utilizing HTC's Ultra Pixel tech, which like the cameras on new Samsungs and iPhones, promises to capture better images with fewer, larger pixels. Our image testers will have to check that claim when we get the retail version of the HTC 10 in our labs. However, HTC smartphones have been using Ultra Pixel tech for several years without making our Best Smartphone Camera list.

HTC went overboard on the interface, which offers a mind-numbing number of ways to customize the look and feel of the phone desktop. More on that later. One thing I do like about the interface: HTC eliminated the app redundancy that plagues most Android phones. For instance, HTC sacrificed its Internet browser for Google’s Chrome, and now there’s only one phone dialer instead of a second one from Google. Of course, you can always change what HTC gives you by downloading and deleting apps.

I've been using a press sample to gather these first impressions, but we only test phones we buy at retail for our Ratings. And so it will be a few weeks before we have the official lab results on this phone. The HTC 10 will be available from all major carriers and many of the larger cell providers in early May. (Verizon began accepting preorders on April 29 and offers in-store previews.)

Here are more of my first impressions.

It’s fast. The HTC 10 comes with Snapdragon 820 processor, 4 GB of RAM, and a camera HTC says has been optimized to launch within 0.6 seconds. I didn’t have a stopwatch on me, but I found that most apps, including the camera, seemed to launch almost instantly. And pictures appeared in the photo-gallery preview window almost as fast as I could snap them.

The HTC 10 also supports Enhanced LTE networks, a 4G-network technology that groups several frequency bands of a 4G LTE network to produce a fatter—and faster—data pipe. This model supports Cat 9 LTE, which means under ideal conditions and network availability, the phone should be able to download data at 450 megabits-per-second (mbps) and upload it at 50mbps. But such networks are not yet widely available and ideal conditions only happen in fairy tales.

Another way HTC says it's optimized phone performance is via Boost+, a mysterious application that HTC says monitors and adjusts applications’ use of memory and battery power to improve the system's speed and efficiency. Can’t say if that worked, but our engineers have ways of squeezing truthful performances from any smartphone. One more thing about Boost+: It allows you to micromanage manage app privileges, clear “junk,” and perform other tasks. But Android Marshmallow, which this phone runs, already aptly handles most of these jobs. 

Great connection. The HTC 10 comes with a USB-C connector, whose main advantage is that it can be inserted into the phone no matter which way you hold it, so there is no "wrong-side up" as there is with micro USB cables. Also, USB-C cables have an impressively large transfer rate—up to 10 gigabits per second (Gbps)—that should mean nearly instant transfers for the mega-size photos and HD videos taken with the phone’s high-resolution camera.

Juicy battery. HTC says this smartphone's hefty 3,000mAh battery will last up to two days with normal use. In our tests, under our “normal” conditions, phones that make such claims rarely last more than a day, so we'll withhold judgment. Additionally, the HTC 10 supports rapid charging, claiming that a near-dead battery can recoup 50 percent of its power in 30 minutes with the included charger. We’ll see about that, too.

Boom sound. HTC has made a big deal about sound quality for the past several generations of its phones, beginning with their trademark dual, front-firing speakers and support for 24-bit hi-res audio, which all appear in the HTC One M9. On that and other models, our testers have noted that these amplified, front-firing speakers are among the best we’ve heard on a smartphone, good enough—and loud enough—to enjoy without headphones.

But I suspect that may not be true with the HTC 10.

On this model, the bottom speaker was pushed from the front of the phone to the side to make room for the phone’s fingerprint scanner/home button. That may be one of the reasons it sounded much tinnier to me compared to the One M9, which is still in our lab.

Complicated customization. This is where HTC lost me. The 10’s interface, which HTC calls Sense, offers quite a few ways to personalize your phone’s layout above and beyond the many options Android Marshmallow already allows. For instance, the Themes app gives you a vast number of layouts from which to choose, each with its own set of backgrounds, icons, and sounds, which you can mix and match. Another feature, called Freestyle, removes the grid that normally keeps app icons in neat rows and columns, allowing you to drag them closer together, even having them overlap just like on a computer desktop. Personally, that kind of chaos is the last thing I’d want on my phone’s desktop.