Hi, Linda. Sorry to hear about your weed problem but that's about what a willow tree is. Willows are generally dirty in that they drop sap, leaves and branches. You are always having to go clean up under them if you want a nice yard. Being shallow rooted, they also make your yard bumpy and hard to mow since the roots like to grow out of the ground. Our town will not allow planting of any species of willow except the corkscrew willow.
For waht it's worth, the wood kind of grows in a spiral pattern and has a high moisture content. That means that it takes forever for it to dry for burning in the fireplace but that doesn't matter since it is difficult to split also. There is no commercial use that I am aware of.
I know that you did not ask, but if I were you, I would have it cut down and the stump ground up. You are still very likely to have sucker shoots come up from the old stump and you want to keep cutting them down until the roots have rotted. About the only thing good that you can say about willows is that they have to have a lot of water to survive so there probably is a fair amout of ground water where it is growing.