The rag jean quilts are a lot of fun to make. No real worries about seams matching and all that but after it gets so big, it does tend to get a bit heavy and bulky.
I did not use a batting layer, just the jeans and flannel. It's still a bit heavy. This will have to be washed by itself, just because of the weight, but I have a heavy duty washer that should be able to handle it without any trouble. It probably weighs about the same as 3 or 4 pair of jeans.