I do use causal curse words quite a bit (damn, hell, shit, mostly). I don't think it's really good or bad, just depends on the context. I am pretty much desensitized to most cursing, but it does depend on the person how desensitized I am because some people curse a lot and some don't. I personally think dropping F bombs constantly lowers the actual impact of the word, it loses its power and becomes just another word. It's the same in writing, if your narrator or all your characters are constantly cursing the actual impact of those words just ends up being lost.