I have a lot of oak leaves in my own yard, and a lot of yards in my neighborhood do also. I love to use the whole leaves in paths and out of sight beds. For my seedling beds and other flower beds I much prefer to use shredded oak leaves. They make a very nice looking mulch when shredded. Large whole leaves often tend to mat and block water from penetrating them. Shredded leaves allow the rain to penetrate and they stay in place so much better when shredded. Even when shredded oak leaves take a long time to totally decompose, but I am to the point in my gardening now that if it takes two years that is fine, I just try to keep piles at different stages, some for mulch, some for compost or just leaf mold.
Now if I had my choice I might prefer to use much smaller softer leaves that break down much quicker(I do pick up quite a few of those also) for the beds, but I like that the oak leaves are tough and last a long time in the paths. I guess here in Alabama the leaves are more important as a sun blocking insulation in summer than a ground freezing preventing type insulation in winter.
