Pros:
-Quad DAC: seriously, music is amazing. If you're not a music fan, then this won't be for you
-high quality mic: it picks up EVERYTHING, very clear and crisp. Also loud music from a concert won't sound distorted so you can take great videos at concerts.
-removable battery (the only and maybe last to have, extremely convenient)
-dual front and rear wide angle & regular cameras
-16MP camera (as opposed to the standard 12MP; there IS a difference, try zooming into a photo) and the manual mode give you a DSLR like experience
-still has micro SD card slot (never will find this on a Google Pixel), I can enjoy thousands of audio books and music MP3s
-IR blaster: now I can change the channel anytime, anywhere, anyplace
-nice slim and thin design, high quality metal back (vs huge bezels of iPhone 7 plus and Pixel XL)
-useful 2nd screen (always on display is really useful with 2nd screen)
-IPS LCD: no need to worry about screen burn in
-military grade rating (don't drop your Galaxy, it'll crack in two places)
-finger print scanner is conveniently placed in the back, easy to reach
-you can download themes just like Samsung
-OS is SUPER FAST, no lag whatsoever, optimized RAM performance
-battery life is excellent. I never really need to charge my phone until bedtime.
Cons:
-camera automode can be a bit slow to focus at fast moving objects (unless you use manual mode)
-camera not the best at low-light (unless you use manual mode)
-the top and bottom part of the phone is not made of metal like the back, but at least you don't get those ugly antenna lines, and it's still durable however
-apparently according to some, the camera glass is fragile if you're not careful
-doesn't have an AMOLED screen (still beautiful but not as nice as AMOLED)
-glass is slightly curved at top and bottom of phone making glass screen protectors difficult to install
-no water-resistant rating (but it's okay for me, I never expose my phones to water anyway)
-OS updates are a little slower than Pixel or iPhone
Overall thoughts: I really like this phone a lot, it's actually the best phone I've owned to date. LG really nailed it with this one and I think this was what the LG G5 should have been. Tons of features are jam-packed into a slim phone. Honestly, smartphones are getting boring, I'm really glad my V20 has all the features I want to keep me happy for the time being. This phone is underrated and people are sleeping on this great phone. If the camera was faster and it had an AMOLED screen, then I would think it'd be the flagship killer.