Hi Deb38,
I just realized I missed your question about wool but I think DahliaM covered it as well as I could. It will impress about 30% or so over time and this is a natural part of how wool performs and doesn’t indicate it is “wearing out” (unlike foam that impresses).
Post #2 here and Post #4 here has a bit more about wool toppers and a link to some manufacturers of wool toppers that are very knowledgeable about wool and are great sources of information (and they don’t mind talking about wool even if you don’t end up buying).
Phoenix