I have shredded truck loads of leaves with my mower every year for the past few years since I retired, I never had time for that before. But the extra work is really worth it if you are in a hurry for compost. I have a large pile of leaves sitting and slowly breaking down that was not shredded, they have been there about a year, by next year they will be ready to use. Shredding them would have reduced that time by at least half, and turning and working the pile would have reduced it by almost half again, adding grass clippings and mixing them in and turning the pile would have even further reduced the time.
