The soakers I bought were size medium and I can imagine them lasting my 8 month old daughter for many more months. They pull on like shorts and cover the diaper all the way around. They're not super snug around the waist but it's the fitted that keeps in the "mess" so it's not necessary for it to be uber snug. These soakers are soft and adorable. They're even my husband's favorite cover when he's brave enough to use fitteds. He calls them "sweater underwear" covers. Any diaper that gets daddy approval earns extra stars in my opinion!
Wool covers require specific care that took me some time to research and learn how to do correctly. However, it is not extremely regular care. As long as the cover doesn't get soiled, it can be worn over multiple changes. If it gets a little wet, you can hang it to dry and it cleans itself, due to it's antibacterial properties. I only have to lanolize my wool about every other month.