In Steve's current monthly survival pack I found the Brazil Fortaleza Pupled Natural (thanks for that one Steve!). It's the first time since the LaCimbali and I are good friends that I tried a Brazilian Coffee in the espressomachine, and I think I now get it when people say "... is a good base for an Espresso blend".
This Bean makes a very nice espresso, I had a very delicous ristretto today as well as quite a good double from it and it's very smooth and balanced, reminds me a bit of cocoa, but that can be due to the cold I just catched up
This bean has no specific special features on it's own if I may say so, but because it's so smooth and balanced I can imagine adding some Zing-Kenyan to it or maybe a Yirgacheffe would give a very nice blend!