My bottom line on this subject has always been to say, "its your machine do with it as you would".
On the subject of Ergos and STIs and how competitive they are compared with Bar cons and DT levers, I am opinion that the real leap forward in technology is the profiling on the sprockets. Modern sporckets are great! The chain will slip across them, under pressure, one at a time, with no jumping or slipping. It some times impossible to tell if it has shifted or not it is so slick. I would be happy to sit down on a hill and change gear using a DT shifter (when the pressure is on in a race I sometimes still find myself grasping for a non existent lever!) if I knew the sprockets and chain would be as silky smooth as they are with a contemporary 9 /10 set up. As for changing whilst standing in a sprint, I never do that any way, ergos or no ergos.
I have really become a sad bicycle rider, in that my only expenditure in life (i.e. only interest) is bicycles. I race regularly but find now that I simply cannot be bothered to keep "improving" my race bikes. When selecting race equipment these days, unless it is positively un competitive, I look for parts that are most likely to give less maintenance or failure problems. In other words, they do not move my sole, the are just tools.
Whereas the bicycles of my youth or before, or even a fully speced up touring bike, cover with "fu fu" lug work and striking paint and chrome.....they do not compare to the Ferrari, they are far more beautiful than that!
Regards
Martin Coopland