Bravo. I don't think I'll ever have enough time to confidently and efficiently set up stobes in manual mode. I'm sure I could figure it out using tables, trial-and-error and other methods, but I don't do it every day (nor do I think I ever will), so there is no advantage to manual flash when I can just set up camera in manual mode, and play around with ISO, shutter speed and FEC and get similar results in about the same (or less) amount of time....I kinda go with what I heard Syl Arena say, that he only uses ETTL when the distance between the lens and the subject are moving....
With all due respect to Syl Arena, Joe McNally, Strobist and all the other advocates of manual flash, they have thousands upon thousands of hours of experience working with strobes and know them inside and out. While it's a good exercise to try to learn manual controls, to me it's a little like the original topic of this thread: if a tool is available that makes your life easier, why not use it?
If I live long enough, I may someday have enough experience to confidently set my speedlights on full manual. But, in the meantime, I figure I paid for Canon's top line strobes so I might as well take advantage of the technology they offer. As so many others have said about the original topic of this thread: it's about the results, not about how you got there.
How about a lightmeter?
Instead of shooting a lot to try to get the flash to fire the way I want, I simply use a lightmeter, set the flash, turn it off, do the next one and turn all of them on, it's done within three minutes, and then I can shoot and move, and no matter if I move so that I have the flash directly to the camera or hidden I ALWALYS know I have the exact same light hitting the subject. That's why I always use manual flash. I have shot with ETTL and found it very frustrating that I had to stand in the same place or the exposure would change, for example having a flash towards the camera suddenly everything is three stops under.
Manual flash sounds difficult, while it's really the opposite.