I use butter in all recipes that call for shortening. I've always said that all-natural butter was better for us than hydrogenated, chemical-laden shortening (or margarine--which is just shortening with EXTRA chemicals to make it look like butter and give it flavor),. And now the health experts agree with me.
Yes, cookies may be a bit thinner, crunchier with butter, but I like them that way. However, if you want to use butter for flavor and health recipes, but want a softer cookie, you can just add a little bit more flour.