I received the xDoria Defense Edge Bumper case for my 7 yesterday so here's a review of it. I wanted to try the bumper to show off the back of the black phone as opposed to having it covered by a case (clear or otherwise).
Much like the bumper for the Apple watch, it is made of machined aluminum and is minimal as far as adding any size to the phone. It is lined with a rubber material to lessen any impact if the phone is dropped. As far as the front and back of the phone, it protrudes above the screen and the back of the phone just enough to keep either side from touching whatever surface you set it on. On the back, they have added an additional piece of rubber in the upper left hand corner of the case near the camera. This is due to the fact that the camera actually sticks out farther than the case itself. Adding this piece keeps the camera from touching when you set it down, put it also means that the phone doesn't sit level when place on its back.
The case is not hinged, but goes on and off easily enough. I found that putting it on from the front and taking it off from the back worked the best. The machined aluminum is actually three pieces connected by the rubber material the case is lined with. There is a piece that covers the top edge/corners and a piece on each side covering the edge and bottom corners. The aluminum stops short of the lightning port and that area of the case is just the rubber material (probably why they were able to make it without a hinge).
Volume up/down and the sleep/off button all work well in the case. These are accented in silver which matches the accent around the front and back (see the next paragraph). The grills on the bottom of the phone are unobstructed as well as the opening for the lightning port. No problems charging with the lightning cable. The opening for the mute switch is, unfortunately, either not large enough or not centered properly. I can easily switch the phone to mute, but it takes some effort to get my fingernail into the opening to switch the sound back on. There are two holes in the top of the case near the camera that I have no idea what their purpose is.
As far as the look and feel of the case I like it. I also have the Apple gray leather case, which I like, but this is a completely different animal. Although they call it space gray, it is closer in color of the Apple watch than to the matte black on the 7. The silver accent they put around the edge is enough of a break between the two to make it less noticeable and I think it looks good. I have to say that the phone is slippery since it is almost like having no case at all. With the 7, this is the first iPhone I have purchased through the IUP and had AppleCare on. It is only for that reason that I decided to go with the bumper (if things go really wrong I can always get a replacement, right?).
Overall it is taking a little time to get used to since it is so minimal. I'm sure I'll revert back to the leather case when I know I'm going to be doing things where I want extra protection on the phone. As of now, I like both the look and feel of it.