Canon spent millions perfecting the system, I paid for the convenience. Why use manual if I can use ETTL and not waste time?
The fact that the flash has different modes would indicate that there is not one mode that works for every photographer for every photograph under every condition.
If you are happy with ETTL then ETTL is the best mode for you. Others may prefer the other modes. Still others use multiple modes depending on the circumstances.
Such is the photography world.
Yes, of course. I didn't intend to criticize other choices. My intended point (obviously not well-made) is that we pay for top-of-the-line products that have been thoroughly engineered and tested to perform certain functions and then sometimes, not always and not directed at anyone on this thread, people get on forums and seem to think it's a point of pride NOT to use the technology they've paid for.
I was simply trying to make the point that ETTL is pretty darn good on Canon flashes and there is no reason anyone should be embarrassed or made to feel less of a photographer is they choose to use it. To me, it's sort of like "P" is for professional. Use whatever mode you want and don't let anyone intimidate you, because in the end, it's the photograph that counts.