The HTC U11 is a notch bigger – about 5-percent taller and wider. It is also slightly thinner, which could help keep it comfortable to hold.
As you might expect, the U11 is also nearly 5-percent heavier.
Both phones are available in a number of colors, but availability varies by region. Here, the variants marked with an asterisk are not currently available in the US.
HTC introduces a feature on the U11: pressure-sensitive sides, which add a new way to interact with your phone through touch. Depending on the app, squeezing the sides of the phone prompts shortcuts and actions like snapping the camera shutter and launching voice-to-text.
Because the edges are pressure-sensitive and not touch-sensitive, HTC says this interface works in situations that can sometimes be problematic for the latter, such as in the rain or when wearing gloves.
At this point, this new addition reminds us of Apple's 3D Touch pressure-sensitive display technology. It seems like a good idea, but its ultimate utility will be determined by how well software developers are able to put it to use.
We've seen several smartphone makers introduce water resistance over the last year, and HTC has followed suit. The U11 has an IP67 water resistance rating.
This year, HTC bumped up its premium flagship display from 5.2 inches to 5.5 inches.
The two phones have a matching 2,560 x 1,440 QHD resolution, which spells out a slight pixel density advantage for the smaller HTC 10.
HTC is sticking with IPS over AMOLED technology in its displays.
HTC is also sticking with off-screen home buttons for the time being. As phones pack in larger displays on smaller bodies, we expect these physical home buttons to become increasingly rare.
Both flagships have fingerprint sensors built into the home button.
The new U11 is packing the latest and greatest Snapdragon 835 chipset, while the HTC 10 has last year's still-capable Snapdragon 820.
The amount of RAM remains unchanged.
The HTC 10 comes with either 32 or 64 GB of storage, but this year's flagship just keeps things simple by starting out with 64 GB.
HTC further helps you out in the storage department by including a microSD slot on both phones, for expandable storage up to 2 TB.
The U11 has followed in the footsteps of the iPhone 7 and ditched the traditional 3.5 mm headphone jack. There's an adapter included, but if you want to go without an extra piece of cordage, you'll need to use either wireless Bluetooth headphones or a pair that plugs into the USB-C charging port.
... but audiophiles don't need to fully panic, because at least HTC is one of the rare makers to include support for Hi-Fi audio in its flagships.
And this year, the HTC U11 includes a pair of U Sonic USB-C headphones bundled in the box, which also offer some active noise cancellation. The HTC 10 comes with headphones in some regions, but not the US or Canada.
Battery size stands pat at a reasonable 3,000 mAh, though many factors go into overall battery life than capacity alone.
Both phones support Qualcomm Quick Charge 3.0 fast charging technology.
Neither the aluminum HTC 10 or nearly-all-glass HTC U11 supports wireless charging.
We've seen front camera resolution creep up considerably over the past year, but the new U11 takes the cake. Its selfie camera has an industry-topping 16 MP resolution (tied with the OnePlus 3T) – which is more than it packs into the rear camera.
Camera aperture (rear)
The 2017 flagship has a slightly larger camera aperture, which should indicate incremental improvements in low-light shooting and depth of field effects.
Optical image stabilization (OIS)
Both phones include OIS to combat blur brought on by shaky hands and/or long exposures.
Both devices support Android Pay, for making payments with the swipe of your phone at participating retailers.
The HTC U11 packs in not one, not two but three voice-activated assistants. Like all recent Androids, it supports Google Assistant, but it's also the first phone to have built-in wake word Amazon Alexa access. It also has the HTC Sense Companion, the maker's own proprietary take. This seems redundant to us, but at least you'll be covered.
Mobile VR headset support
The HTC 10 came out in May of last year. The HTC U11 is available for pre-order now. In the US, it starts shipping and hitting shelves on June 9.
Starting price (full retail)
The original list price for the HTC 10 was US$699, but it's currently available unlocked through HTC for $599. Then again, it's only slightly more expensive to pre-order the $649 HTC U11 directly from HTC.
Of course, prices may vary depending on carrier and payment plan, and there may be even more favorable discounts on the generation-old HTC 10 available elsewhere.