I must stick my neck out here and say I somewhat support Indiancoffee on this one. Living in Indonesia we have some of the most fabulous Arabica in the world- everyone knows that. We also have some of the rattiest, nasty, gnarly robusta. Now I certainly do not use any of this stuff- although it is obviously thick on the ground like snow at Milehigh stadium in January. Recently the work of people like Pierre at WAGRO have highlighted that there are some gourmet robustas that deserve a second chance. These include washed and well prepped robustas from Madagascar, Uganda, India (of course). I would add Indonesia, but in reality there is still work to be done here on the quality of robusta.
I am no real fan of robusta- but having lived here now for 7 years most of the coffee I drink at roadside stalls is robusta. My pallate has begun to pick through the rubber, wood, burnt corn tastes. Also with all the fabulous Arabica available...well I am spoilt for choice :grin:
I would say for me a little (and I mean a very little) robusta does work well in my espresso blends.