A fairly solid adventure, Citadel does have the potential for coming off the rails and having a lot of continuity problems early in the adventure. It is tightly paced, so a grevious injury that a player might want to use rest to heal can present problems that wreck the timeline. The party can also make some role play decisions that might knock the plot off course.
I was especially careful to make the forced companions almost invisible or helpful so they didn't feel as though they were hindered or burdened. I also worked hard to keep the pace of the adventure very high, so that the party is more worried about the environment and immediate threats than to stop and consider the downsides of traveling with NPCs.
I would suggest that a GM be prepared to provide unexpected sources of healing. I've done this once and it keeps the adventure moving at points where it really should not bog down.
[4 of 5 Stars!]