Well maybe someone will experiment and tell us what they find. I have seen a lot of people getting hurt on ladders even 1 story up and it ruins an entire season, so I am all for anything that keeps you on the ground.
I'm going to try the gutter vac idea as soon as I can... I don't even own a shop vac, but I will have to get one after the first of the year. Looks good to me... one guy said in the reviews that it not only sucked up the wet leaves, but the standing water, too!
Right now, I have a scoop that I'm using... it sucks, but it works.