[Daishichimaru]

Animating the opacity works, yes, but it creates more side effects than it's worth. Screwing with the material opacity doesn't touch specular levels, so you can have transparent text and a big specular flare blocking everything from your 'invisible' text. This can be solved by wiring the parameters together, but then you can't play with either value independently and if you have opacity mapped with anything it doesn't work well at all. The visibility controller acts independently of texture channels and actually mutes the specular levels automatically. It's also a lot easier to get rid of the changes if you so decide when you can just delete a controller instead of key hunting. Just something to keep in mind.