Ok. I was reading the previous thread about light transmission through different scopes....here's my question.

I have 3.5-10X40 Leupold VX3 on my "go to" rifle. If I went out and spent $2000 on a Swarovski Z6 scope with it's 30mm tube, would I see much difference?
Or one of their Z5 series with the same 1" tube as my Leupold?

I want to be able to see as well as possible at daylight and dusk, but I'm not much of a fan of an objective over about 40-42mm since I like my scopes mounted as low as possible.

What models of scopes would I have to go to see a REAL difference from what I've already got? Or would the difference be minimal?