by far and away the most common fault with most shimano road stis is that they simply gum up (through lack of lube) or jam up when the cables fray. They are (accident damage asides) surprisingly durable in most of their 'washing line' incarnations. Later ones I am yet to be convinced about.
If you want to pick a 'sensible' campag ergo for use with fairly modern kit then the 2005-2007 model veloce is (to my mind) pick of the bunch; not too expensive, sensible LH shifter that will work almost any FD, with internals that are very similar to the preceding ten year's worth of ergos, (including the 'record' models) so no nasty surprises. These are however not perfect; springs occasionally break and if you sweat lots the thumb button pivots can go manky if you don't lube them. The whole business with 'G' springs is an arrangement that is likely to wear gently into senescence rather than suffer catastrophic failure.
Ultimately it won't last as many shifts as a shimano STI without wearing, but whilst spare parts are (were) readily available having new G springs fitted every 15k or so (and a new index wheel if that was bad too) wasn't prohibitively expensive in terms of spare parts. I have a couple of sets of veloce ergos and they do fine on bikes that see mostly 'sunny day' use and don't do that many miles. However if you beat crap out of a bike every day, then you are better off using something else; veloce ergo rebuilds may be once every year or two otherwise.
Ultimately the whole business of integrating the shifters and the brakes is just a needless complication for most riders who are training, touring and/or commuting. I particularly don't like that fact that they suck you into lots of (mostly needless) gearshifts and into using just one or two riding positions. I also don't like the fact that they cost a small fortune (they are often the second most expensive part on a bike) are easily damaged, difficult to service, go obsolete and limit your choices of other equipment (like mechs, numbers of chainrings, brakes and even handlebars).
It surely wouldn't be beyond the wit of man to make an ergo/STI with
1) an adjustable brake cable pull, that could be made to work any brake sensibly and
2) to have an index mechanism that has the index wheel/mechanism readily accessible so that it can be changed for another as your bike requires.
But that would be too easy, wouldn't it?.....
So for now there is much to be said for things like Kelly's take offs and the like; they at least free up your choices a bit, and are less likely to leave you with a bill of hundreds of pounds for stupid shifters if you have a small prang....
cheers