Pro Industry leading camera
The camera may only be rated at 12MP, but it uses 'dual-pixel' technology which means there are actually two sub-pixels for each pixel. These dual-pixels will be able to capture much more detail than a regular 12MP camera. Each pixel has also been enlarged, allowing more light to enter. This means that lowlight photography will be drastically improved.
Pro Fantastic display
The 5.1" 1440p Amoled display is the best display ever put on a phone. The Amoled display technology allows individual pixels to turn off (IPS LCDs have the whole backlight either fully on or fully off which is why they still produce light on a totally black image), meaning that black colors truly are black. Colors appear to pop out of the display as well.
Older generation Amoled panels used to suffer from screen burn-in, however this issue was addressed last year and should no longer cause any issues.
Pro Expandable storage
The Galaxy S7 has brought back the SD card slot (the Galaxy S6 didn't have the slot), which allows for 2TB of theoretical storage. The only problem is the largest micro SD card on the market currently is 200GB, but that's still a lot of storage. Because there is a SD card slot, you can add more storage after buying the phone - something not all phones offer.