If you're in the bracket of "100 mbps down is fine for me" then you most likely do not care about the upload speed at all. About the only advantage for the average person would be "Your iCloud backup goes faster".
1gig/500meg would be a huge step forward. I'm currently on the highest most bestest plan that my ISP (Astound) offers. And it's 1.2gig down, 50 mbps up. That's not a typo, FIFTY up. I'm a techy and even I know I don't need 1.2gig down. My house is wired with CAT6 because I dragged it around, but my main switch is still gig. So... I can't even enjoy the increased download. The only reason I stepped to that highest plan was to get more upload than the 20mbps they previously offered.