i guess it depends on how fast you move. i haul a**

so the stroller is not only helpful, it's critical. i also bring a backpack full of ponchos, water, handsanitizer, snacks, change of clothes for the girls, my whole Unofficial Guide 2 WDW (2006).
So not only does it help so that we can move faster, but it carries all of my stuff. We sure got our money's worth on our double last year. My sil's were both with us, and between the 3 families we had 2,3,4,5,5,6,12,15. One sil had her own double for her 2 and 4 yo (though he rarely rode with her), i had my double (the rentals) and in it were a 5 and 6 yo next to each other with their feet hanging out the side or tucked up, the other 5 yo where the 'feet' should go, and my very light 3 yo sitting on the hood of the stroller. it was quite the site but man could we hustle. the next days, sil with one child got a single b/c my then 5 yo doesn't like to be in such close proximity to people.
anyway, i don't *ever* use strollers at home with my kids, and haven't since my youngest turned three...usually i just walk slow enough for her to easily keep up. but for disney the week between xmas and nye, time was of the essence. we had to get as much as possible done by 10 am and the strollers made that happen.
also fwiw, i tied a bright pink shawl to my stroller so i always knew which was which and i had been alerted to the fact that CM's are always moving strollers around in an effort to tidy.
katherine in atl