Pro Great camera, especially in low-light
Samsung has reduced the resolution to 12MP (the S6 had 16MP), but they have changed the way the camera works. Each individual pixel is larger which allows more light to enter - this means brighter looking pictures even in very dark situations. They also use dual-pixel technology, which makes focusing laser fast. The camera also protrudes less from the back than the S6 (it just barely sticks out now).
Pro Amazing display
The S7 Edge has a 5.5" 1440p Super-Amoled display. It has a very high resolution which means blocky text and grainy images are things of the past - it's got enough pixels that it will work great even as a VR (virtual reality) display. The Super-Amoled technology allows individual pixels to turn off, which means that black colors are true black (IPS panels need to keep black pixels illuminated which means that very dark blue glow you'll find on most screens when displaying black). Colors really pop as well.
Pro Good battery life
The 3,600mAh battery is large enough to last a full day, and Samsung boasts that you can binge watch an entire season of Game of Thrones without needing to charge (these claims have yet to be tested, but users are reporting 7 hours of screen-on time during mixed use which is still impressive).
Pro Comfortable design
The Galaxy S7 Edge has a curved screen on the front, as well as curved glass on the rear. The rear curve makes it groove into your hand better than regular corners on most phones. On the front of the screen, the edge invites you to swipe all the way to the side of the screen, and there are features that take advantage of this. Swiping in from the right edge brings up panels which you can customize: quick one-touch to call certain contacts, quick launching apps - you can configure it to whatever you want.
Pro Very fast performance
Depending on where you buy the S7 Edge, you could either get the Snapdragon 820 (America), or the Exynos 8890. Both processors are very good, however the Snapdragon 820 offers better GPU performance for gaming, and the Exynos 8890 provides slightly better battery life and CPU performance for opening apps and performing calculations.
The Galaxy S7 runs TouchWiz software, which is known for its abundance of bloatware. Bloatware is the term used to describe pre-installed apps that add little to no functionality. Samsung's offerings (S-Voice, Chat-On, Flipboard, Kies, Samsung Hub, and the list goes on) are often inferior to Google's offerings and/or third party apps.