Expecting your website to be identitical across every browser is not the goal. You need to build sites that respond to the capabilities of the user's device, and progressively enhance to get better as more features become available. If the website is less wide to account for the scrollbar on browsers where it can be that's awesome, and if it's full width on browsers that don't have the gutter feature that's OK too.

Critical functionality should work everywhere. Then users should get the best experience possible that their browser supports on top of that.