I'm actually using the Voyager (black) right now with my 6 Plus, I got it with my premier discount.
The case is very good. Looking at mine now I don't have a gap by the volume buttons so maybe the case you saw wasn't closed properly.
It has a good size lip in the front so if you were to drop it there is no way the screen will touch. The biggest problem is getting the case off, you need to put a coin on the bottom right and literately pry it open. If you decide to get this one make sure you are happy with it before going through the pain of having to take it off.
It also has lifetime warrenty so if you do drop it and the case breaks you can contact them for a warrenty exchange.
Overall I think it's a great case because I don't have to worry if my phones going to get damaged.
It also comes with the belt clip that doubles as a stand to hold your phone if you wanna watch something.