I also have a Vidabox iPad mount.
The miters are perfect on mine. The build quality is very good, solid frame. I used some muscle to close the miters, before screwing it tight. Maybe you need to spend more time at the gym, Corey.
I've had the iPad in the mount, sitting on the kitchen counter, 2 feet from the eventual wall install location.
I bought the iPad for the Nuvo MPS4 app, to control my Nuvo system, to replace a Nuvo keypad.
The app isn't perfect - about 1/5 times it gives me the message 'server not found', and I have to exit out of the Nuvo app, open something else, close it, and then re-open the Nuvo app.
So, I'm hesitant to mount it permanently. The chosen location would replace the Nuvo KP, so I'd lose control from that KP.
The mount itself is very nice. I bought the Vidabox catx extender, haven't tried it yet. If you have power in the area, a recessed box large enough to house the iPad AC/DC convertor should work fine. I have a few cat6 cables in the Nuvo KP location to choose from, home-run to the closet. The iPad will run forever with continuous power. Vidabox told me the max recommended distance for the iPCX extender was 50 feet. The Vidabox iPower charger max rec'd distance is 300 feet.
When I have a whole-house control system, the iPad will definitely be permanently mounted, using this Vidabox mount. It's very high quality.