I've run SOS twice and Graveyard Shift once. After playing SOS the first time I had to modify the rules (originally you only had one movement or action per round) to make it quicker as it went for over 8 hours! Everyone had fun, though.
I have now also run the latest campaign (Mall of the Dead). This has been my favourite so far and gave me inspiration to tweak the rules some more. The system worked fine but I thought it was too easy for the players to defeat the zombies so I added the fumble rule (1 on a D10 is an automatic failure for any action).
