Timeline or Script Animation, hard decision

This is what I wonder today. Where is the limit to take one or other step?
I have made a lot of banners with script animation, but I realise sometimes it is faster doing them in timeline. Where is the limit? Is it depending on how big is the film? I tend to think that script animation is better if the customer is used to make a lot of changes (speed, transitions, elements). But building it costs more time than timeline.

Timeline is comfortable, what you see is what you get! Coding is for a programming point of view. I would use code in long animations, not in banners. But, scripting is more expeditive, what you do with programming you hardly ever do with timeline. I always say I can do many things programming that a designer can´t see.

Making the intro animation for a microsite, for example, I would use code. Why? Because there would be more changes, be sure! And probably the animation would take longer. There´s other aspect you can use with programming, the factor or randomizing! You can make animations so they will never be the same (random colours, random movements, random shapes). I like it!