The main reason I've left ample room for adjustment is to get the Phantom to fly nicely. Most cameras are not center weighted. The GoPro is light enough for this not to matter, but I have to fly with my Samsung to the side. Fortunately, as it is not wide angled you cannot see the propellers or legs.
The full mount is actually set further back on the fuselage, as heavier cameras will be biased towards a more central spot on the drone. I just want to stress to any other customers that if you're planning on using a very heavy camera on this mount, you must take extra care to keep your Phantom centre weighted.
That means you need to account for the battery being at the rear, and your camera slightly to the front.