Barcons are right where you want them. And yet they are put in the touring ghetto.
Barcons were pretty much standard equipment on Cyclocross bikes before STI/Ergo came along so they weren't limited to touring bikes.
When you need to shift across 2 or 3 cogs at a time, any linear motion system, indexed or not, has a huge advantage over STI, RapidFire, etc.
You can downshift up to four cogs in one lever sweep with both STI and Ergo shifters. Ergos (pre-07 for all models and '07 Record and Chorus) let you upshift the entire width of the cassette in one push of the release button.
STI/Ergo are clearly superior to barcons when you are standing while climbing or accelerating. You can easily reach brifters but not barcons from the hoods.