A 50mm objective messes up the balance of a lightweight rifle (yes, that extra 1/4 pound makes a difference on a 5 pound gun). If I wanted a brighter image, I'd spring for a better scope with superior lenses and coatings, not a bigger, heavier one.
Of course, a larger exit pupil gives you a tiny bit more leeway in the placement of your eye behind the scope. If the exit pupil is 3mm, your eye must be perfectly centered in that 3mm to get a perfect round field of view and to eliminate parallax. If the exit pupil is 7mm, you have a little wee bit more wiggle room. Your eye could be a mm or so off and still see the complete field of view...but parallax could exist.
If this sounds a bit ridiculous to you...I agree completely! However, CGN is loaded with folks who can't shoot a moose at 100 yards without monkeying with an adjustable parallax, a zoom dial and a BDC turret, so I thought I'd mention it!