i went on Friday and Saturday. Friday was dead. Walk ons and near-walk ons on everything.. all... day. Except Tatsu for a period of time had a full line but that's it. What a great day. Me and my friend rode X2 three times in a row without leaving the station. Saturday was a different story. Pretty packed. We got in 10 minutes early and were able to walk on X2 and Tatsu in the front seat with no problem, but soon after that, the crowds got pretty heavy. Not too bad though. I think the longest line was Apocalypse which was like an hour. They were only running one train, and it was closed for a good portion of the day. Some rides such as Scream and Viper were walk-ons the whole day though.
It was my first time going to SFMM, or on any decent coaster really, in eight years. I was very pleased and had a great time. Scream and Tatsu are a lot rougher than I remember, but still great. Scream is actually a lot better than I remember. I always remember feeling underwhelmed by it but I absolutely love Scream now. The weirdest thing is I always hated Viper, but I rode it three times yesterday and I love it to death now. SO much less rough than I remember, and way more fun. I think it's because I'm tall enough to where my ears don't get bashed by the shoulder restraints. Say what you want about Viper, I adore it.