I've gotten a group together on Roll20 and have started running a Dune campaign using my Cortex Plus hack. The four players have been really great and enthusiastic for both the system and the universe in which we're playing. Two players are old friends, one is a guy that I met on the Cortex Plus Google+ group, and the other I met on Roll20 and is playing from Mexico.
Three of the four players have not had Cortex Plus experience, but are learning quickly. The finer points of Assets and the importance of acquiring Plot Points will be their next big milestones in learning the system. It helps that they like the idea of the system and are enjoying the narrative power that the system gives them. I did the "Ask the players questions" thing during the first session and the player didn't know what I was asking - she didn't know the answer to the question that I was asking (that's generally the GM's job to create that). When I explained that I was asking HER to help create that part of the story, she was bowled over and went with it. It was great to watch her enjoy the new-found freedom that CP gives players, over less narrative systems.
It's been challenging coming up with the plot-line and making sure to incorporate all of the things about the characters that are important to them, but it's coming along. And there's a lot of pressure to present my most beloved fictional universe well in the RP setting, but I have a general plot-arc in mind and it's been running pretty smoothly and everyone has been having a good time. The group has agreed that, while the plot starts on Caladan, they want to be RPing on Arrakis and have that experience sooner than later.
Also, because this is the first time that my hack is being used, to my knowledge, the players are also my play-testers. Already, I have several ideas for creating a second edition of the game. Mentat calculations, created in the vein of a Leverage-style wrap-up flashbacks, and firming up distinctions top that list. I'm also thinking of adding a House creation system as well as a House-against-House system akin to the nation against nation system from the Cortex Plus Hacker's Guide.
If you're interested in following our RP journey, I'm chronicling it HERE on Obsidian Portal.