We played a one-shot of this one last night. It went well, although suffered a little from first time play (as GM I went a little easy on the players at the beginning, some rules issues, etc).
For a one-shot, the characters ended up being made too individual - it would have worked better if everyone was in a group (afterwards, someone suggested a sleep-disorder center, which would be perfect). A bit more time for me to think about some nightmares for each character would have helped too... two of the ones I came up with were pretty strong, but the other two were not. Having the group tied together from the beginning would help here too.
The rules work well, and the tension between wanting more dice and wanting to avoid mechanical consequences of using them was very effective.
I'd like to run this again, I think my second try will be a whole lot more fun. Especially with either setting things up better for a one-off or playing a whole story out.