Ya, I see what your saying, it's hard to give it a metric, to quantify, but I feel that the 30mm gives a wider view, and I feel I can get my target in the crosshairs quicker at close range, perhaps I'm just used to it now, but with James's 1" zeiss it feels like looking through a tunnel in comparison. I have had a few circumstances where there was deer at close range and with a 4-12 VX-II it took me a second to figure out which one I was looking at with the 1" tube and 4x magnification, the 2.5 and 30mm just gives me better peripheral.
The Nikon 7 I now have is a 50mm, as per what you say about light transmission and truck hunting, I've had better luck at first light, if you can get to your hunting spot before suns up you can catch the game coming out of the fields, thats where I appreciate the larger objective, as for it being heavier, your not wrong, but the 50mm vs. 40mm makes very little difference to me slung over my shoulder walking through the bush, a shorter barrel or carbine makes more difference in my opinion.
But... I'll give the scope a go for a year or two and see if my opinion changes, I just got it and have only had it out once so far, been hunting with a short .303 mostly.