Well I have the same question.
I personnaly spent more money on Gold Tix, so i didn't have to get there 4 hrs before the doors opened. I've had enough of waiting around for long periods of time like at Milton 'Sodding' Keynes.
I plan on turning up about 3pm, getting in about 4.30pm, and still having a good line of sight to the stage (inside the pen).
If i'm more than 50 yards away form the stage, then there's gonna be some fighting.

I don't need to be next to the barrier, right up Jon's nose, but i do expect with Gold Tix, to be pretty damn close.
Isn't that why we paid more for our tickets???