Mix doesn't work for me. I log in and wherever I try to go it takes me to the profile page. I've tried to complete that but it doesn't save any responses. Doesn't matter what browser I use (I use Firefox but tried IE) or how many times I empty my cache.
As its web 2.0/3.0 perhaps you could complement these sessions with some online coffee break sessions using webconferencing for those of us outside the US?
This is about the user experience. Ask "What does the user need at a minimum" then do it. Then release more functionality as a feature without the user recognizing that upgrades are occurring. usability will be/is a huge competitive advantage - new applications have got to feel intuitive and searingly fast, got to be available now (or sooner) and must be stealth-upgradable.