HTC had a rough year in 2015, but the HTC 10 has been improved in a number of different ways. Gone is the "One M" branding, as well as the disliked 'HTC bar' that took up space on the front of the phone. The UI is more streamlined as well.
Pro Great build quality and materials
The aluminum uni-body design is back, this time with some improvements. The power button has distinguishing ridges, the 'HTC bar" is gone, and they removed the bottom speaker helping it achieve almost 5% higher screen-to-body ratio. On the rear is a massive chamfered edge, which catches light differently and makes holding the phone feel more comfortable.
Pro Clean, simple UI
HTC's Sense 8 UI borrows heavily from stock Android, making minor additions and revisions instead of a complete re-haul. Instead of including multiple apps (a gallery app from HTC and one from Google for example), they have mostly gone with Google's apps.
Some unique features are the "Freestyle" layout, which almost acts like a personalized wallpaper/homescreen hybrid. You can add stickers that fit the wallpaper's theme, and assign them to a task then touched. These aren't restricted to an app grid either. This helps keep your home screen look clean without removing any functionality.
BlinkFeed is also back, and is the best implementation of 'bite-sized' information. Samsung and others have tried copying it, however HTC continues to excel in this area. BlinkFeed is a feed of information that almost acts like a massive widget on the leftmost home screen. It can pull information from social media, news sites, and make suggestions based on contextual data (such as good places to eat near you around lunchtime).
Pro Amazing audio quality - both speakers and 3.5mm jack output
HTC is using a new strategy when it comes to speakers - they are using a front facing tweeter (focuses on high frequency) in the earpiece and a speaker in the bottom (focusing on the bass). It might not be the dual-front facing stereo speakers of yesteryear, but this provides space for a larger screen without making the body of the phone larger, and also doesn't compromise on audio quality
HTC is also using a DAC, as well as a dedicated amp for each speaker. The phone also supports Hi-Fi audio, putting this in the contest for best current audio experience on any phone.
Pro Great performance
In GFXBench 3.0 onscreen, the HTC 10 scores 52 fps on T-Rex and 29 fps on Manhattan. This is in line with the Galaxy S7, and about 50% better than the Galaxy S6 and Nexus 6P.
For the offscreen GFXBench 3.0, the HTC 10 achieved 90 fps in T-Rex and 47 fps on Manhattan. This is just a hair slower than the US Galaxy S7 variant, but ahead of the international Galaxy S7, Galaxy S6, and Nexus 6P.
In Geekbench 3: single-core, the HTC 10 is just a hair slower than the US Galaxy S7 and slower than the iPhone 6S Plus, but faster than the international Galaxy S7, S6, and Nexus 6P.
Pro Good camera
HTC has tweaked their 'ultrapixel' idea - this time they've gone with a 12MP sensor with large pixels (although they aren't as large at the 4MP camera in the M7 and M8, but considerably larger than the M9's 20MP shooter).
Colors can be muted in daylight shots, but the HTC 10 nails lowlight shots. No doubt the OIS and laser-assisted focusing helps here.
Pro Great multitasking performance
With 4GB of RAM, the HTC 10 can store many apps in the DDR4 RAM without needing to re-load them. This saves a bit of battery life (the processor doesn't need to work hard loading the app back up from scratch), but the more significant benefit is the speed at which users can switch between apps.
Pro Really good screen quality
HTC uses the newest IPS LCD 5 display, which can produce very similar saturated colors that you'd find on Amoled panels, or in the settings you can change it to be more realistic looking - like a traditional LCD panel. The screen also responds faster than any other display out there, however this has never been a problem before.
Pro Lots of storage available
The HTC 10 starts at 32GB of storage and some markets have a 64GB version available - there is no 16GB model. This storage can be expanded through a SD card, adding an additional 256GB. This SD storage can be used for anything including apps - not just media like most Android phones.
Pro Beautiful finish
HTC was one of the first manufacturers (other than Apple) to put effort into making their phones look great - starting 4 years ago with the HTC One M7. This trend has continued with the HTC 10. The aluminum body is only broken by 2 flat antenna lines on the back, and the whole rear edge has a massive chamfered edge which catches light and reflects it. It's a beautifully elegant looking phone.
Pro Great fingerprint scanner
The fingerprint scanner doubles as the home button, and is located centrally on the bottom chin. It doesn't click - it's just a touch-capacitive pad. Fingerprints are read quickly and extremely accurately, and the button is located on the front where you can press it while it's sitting down on a desk or table.
Con Lack of exciting features
While the LG G5 has it's modular bottom, the Galaxy S7 Edge has that edge with software to enhance it, and the Nexus 6P has pure stock Android and will get the fastest updates. The HTC 10 lacks a single headlining feature, and even the design is a small evolution of the M7's original design 3 years ago.
Con New charging port
Old micro USB cables will not work with this device, meaning if you lose or break your cable you will need to buy a new one instead of using an old cable you had lying around. If you need to top up your phone away from home, it will be much harder to find a suitable cable initially.
Con Unpredictable battery life
A 90 minute full HD video on 100% brightness drained the battery by 22% - a poor result - which is much higher than the ~16% we typically see. However, while web browsing over WiFi it scored 8 hours - a very good result - beating out the Galaxy S7 (7.6 hours), iPhone 6s (7.45 hours), and the Nexus 6P (5.65 hours). This is a new phone, so perhaps a software update can stabilize the battery life.