I don't know if I'm considered a "power user" but when deciding on a new phone the features I was looking for (at least 32gb of on board storage - it has 64gb!!, expandable storage, current high end specs, removable battery, and great audio, great camera, great fingerprint sensor (very convenient) not Samsung - not that I wouldn't recommend a Samsung phone) were only offered by the V20. So my choice was clear. The runners up were the pixel (no expandable storage or reliable battery, OR AUDIO JACK!) and the galaxy edge (no removable battery and I wanted to venture away from Samsung). To be honest, the phone I really wanted was the note 7, but that was a disaster.
Back to the V20, it's great! I'm a headphone enthusiast, so that quad DAC has been great. I installed the 128gb memory stick from my last phone, Note 4. Listening to music has been a joy, through the audio jack. The speaker is less than stellar. There are other phones that are louder and clearer. It isn't bad though, I listen to podcasts, watch YouTube and it sounds good but the speaker doesn't use the DAC. I'm sure it'll be just fine for the vast majority of people.
Performance is smooth and fast. I went to the developers menu and cut the animations in half so it feels faster and more responsive. If you have an older or newer phone and felt like it was getting old or sluggish, I recommend trying that before getting another phone. There were a few times when the phone froze for a second or two, scrolling became unresponsive. I'm not sure what may happened. It might have been updating apps or I was jumping around between apps and games and video and audio too much or Nougat was doing something in the background. Since the problem fixed itself quickly, I wasn't really able to diagnose what was going on. Generally speaking, the phone is fast and fluid.
The camera is fast and takes great shots, even on automatic. I hear manual is even better but I haven't tried it yet. And with 64gb and expandable storage, you can take MANY photos and videos before worrying about how much space you have left. It takes in a lot of light, so low light performance is really good. You can still see the digital processing so it isn't gonna replace a good DSLR or other high quality camera, but for a phone it's definitely one of the best, if not the best, easily competing with the pixel, galaxies, and iPhone 7. So far, my only gripe is that the quick launch shortcut (double tapping the volume down while the screen is off) is hardly quick. I've found it faster to just unlock the phone and launch the app. :/
Security. The fingerprint sensor is fast and responsive. You can register multiple fingerprints, so if you have a bandage on your index tip, like I do right now, you can use your middle finger (or pinky, if you like) or your other hand. I was delighted that it didn't have trouble reading my fingerprints, as I've had trouble with them in the past. It does require some technique though. Others, including myself, have found that it can take multiple attempts for it to register. I've discovered that because the sensor is on the back, your finger isn't always where it needs to be. Your finger slides onto it or it rolls. And that will lead to an error in the reading. But if you tap your finger on the sensor, you won't have have problems. I think I would've preferred to have the sensor in the front. Another thing about using the fingerprints is you have to create a knock knock code. There are times when it won't let you use your fingerprints. So you better pay attention when you create it or you may get locked out of your phone.
Bonus features, aka gimmicks. Qslide (a quick mini window app launcher not unlike the Samsung Note's floating, multi window tech) is neat but has limited functionality. It is limited only to default apps like phone, messaging, email. It doesn't support Gmail or hangouts, or any other third party alternatives, which is a bummer. Another big disappointment is that, on Verizon, the only Smart feature available is the battery saver. Boo Verizon! There are workarounds for enabling some Smart features like launching a default app for when you plug in to the audio jack or connect Bluetooth, but the feature I wanted most, when to automatically turn WiFi and data on/off based on location, was completely disabled. Normally, you would set up locations, home or work etc, and based on your location it would automatically switch between WiFi and data. A great feature that you would normally have to hack into your phone was built in and disabled! A month later, I still find that aggravating. WHY VERIZON?? At least, give us an answer! Verizon has a history of gimping phones and installing things you don't want or need. For example, my Note 4 and galaxy S3 were supposed to have fm tuners but were either taken out or disabled. Other than that, being able to customize the bottom touch screen buttons is a welcome feature. The wallpaper options are neat, like the 360 or animated wallpapers, or the wallpapers that use the first initial of your signature and superimposes it on the image. It would be nice if they let you choose the colors and position of the initial, though. Samsung-style system wide themes are a nice touch, although there are only three options at the moment. Hopefully, more will come. I really like the way you shrink the screen the by sliding your finger across the menu buttons in the direction you want to screen to be positioned (left or right). The memo app is odd because it requires a stylus that should've been built in, like with the Note. The second screen is an odd duck. It's too high to use one handed. Because it's an lcd and not an amoled, you can see where the screen ends and the camera begins which can make for a less than uniform look at times. It isn't bad, but you notice it from time to time. There are lots of ways to customize so you can keep it from getting too cluttered. I try to use it but I usually find it to be the least convenient way to do things.
The battery is my biggest disappointment. I wish it were bigger. I would gladly take a thicker phone if that meant it would survive a whole day of heavy usage. As is though, it's fine. It'll last an entire day of occasional phone calls, messaging, Internet browsing, Twitter, and an hour or two of YouTube and podcasts. But that's because the battery is brand new. Put a year's worth of cycles through it and that'll change. That's why having a removable battery is so important to me. I don't upgrade every year. I always plan on keeping it over two years. I mean, why get a new phone the second you finish paying off the last one? I don't do that with cars or houses or anything else.
So, all in all. It's a great phone. It should've had a larger battery, the second screen is more of a novelty, some of its design choices calls for a stylus that isn't included, Verizon killed the Smart features, it freezes sometimes, I miss having an always present home button, I do prefer the warmer tone and true blacks of amoled screens. But it has the best audio(through the jack, also it has a jack!), great camera, especially in low light, fast and powerful, expandable storage, a removable battery, and running the latest version of Android. Too me, this is the most future proof phone in the market. And that means a lot. If that is what means the most to you, then this is your phone. I will also add that Verizon sells this for $200 less than the suggested retail price at around $670, another bonus, which also makes this one of the cheaper options for flag ship phones.