You don't have to remove leaves, just get them to where they go, that's a huge plus. I would say it hinges on how many trees, wet or dry leaves. Around here we have giant oaks and when the leaves get wet they want to glue them selves to the ground. So dry vs wet and how many.. Low side 4 hrs high side 6 hrs.
My place is 1/3 acre and I have 5 of the giant oak bastardos with a crap load of bushes. Its every bit of 5 or 6 hours, if I let them build up. They will get 10-15" deep. If I keep up with them its easier on me and the time is essentially the same. That includes getting them away from house and bushes, into containers to dump after collection. I use the blower, a Little Giant HPV and just found a used bagger for my ZTR at a decent price.
I'm thinking this year of offering the two or three trip package.