I virtually always brew ales, and usually fairly heavy and/or dark ones, so I don't generally worry about clarity. If a recipe specifically calls for Irish Moss, I add it, but most of the time I don't. I've never added gelatin. However, my beers are usually pretty clear anyway, because I practically always rack to a secondary, and very very often the brew will sit in the secondary for weeks and weeks. It's not so much that I'm concerned about clarity. It's just that I seem to never get around to bottling a new batch until I start to notice that my drinkable supply is starting to get low.