If you're reading this review you already know what this case is for: total protection. It is expensive, but not nearly as expensive as replacing a S8. The case is two halves, front and back, that snap together and seal against water and dust. Though the case completely surrounds the phone it is not what I would consider bulky despite adding some length and thickness. I'm a bigger guy and the case still easily slips in and out of my front pocket and sits inside it comfortably. The aux port is sealed with a threaded plug (which requires the included adapter to use) and the USB-C port is a hinged door. The USB-C port is easy to open and gracious in size and shouldn't interfere with most cables. The aux plug can be a bit of hassle to unscrew (more so if you install it too tightly), but with the rise of wireless audio that's a non-issue to me. The fingerprint scanner, camera, and flash are three separate windows. The window material doesn't seem to effect the picture quality too much that I can tell as long as you do your part and clean your camera and the window before installation.
The screen protector is very clear and responsive. As others have pointed out in other reviews across the internet there is a SLIGHT problem with the screen protector, however I feel it is exaggerated. The edges of the cases screen are curved and fit the phone well, but it does not adhere to the screen like standalone protectors so there are are points where there may be slight separation. It does NOT result in bubbles, but you can tell where the protector is against the screen via the "rainbow" effect. You may need to adjust your typing habits if you press extremely lightly, but it is expected from adding a layer of anything over a touchscreen.
I have not noticed a sound quality issue with the case and there is still adequate volume. I'm not aware of a call quality issue: no one I've called have mentioned having issues understanding me talk.
The reasons it doesn't get the fifth star:
The case is great and conveniently that's that BB describes 4 stars as, but not perfect. The aux plug is attached to the case with a small tether, but when the two halves are separated the tether easily slides off its mount (it fell off no less than five times while installing my phone) and the plug can get lost. It's easy enough to reinstall, but the odds of losing it during installation are moderate. The case snaps around the edges, but there are spots where it will is more difficult to do than others. For me its between the volume and brixby buttons. It is still waterproof (tested per instructions), but not sitting flush is visually aggravating. Next, the material on the face half has a nice rubbery feel that is easy to hold and I love it. Unfortunately, that material is ONLY on the front (which is basically only around the screen) with the back is a slightly textured plastic that has no real grip feel to it. Lastly is the cost. Quality products demand a premium, absolutely, but this case is nearly double the cost of some of its direct competition (Otterbox, for example) and four times the price of the "average" case.
Do I NEED this level of protection considering the cost of the case and water resistant feature of the phone? Probably not. Do I have total peace of mind with this case on my phone? Absolutely.