This is a fantastic place!! I have been there several times. I was also at the old location before the new one. The organ is very big ( for a theatre organ). It is connected to TWO pianos, a grand and an old upright. It has all kinds of "toy counter" , bird whistles, percussion instruments. There is also some "special effects" which I won't spoil for you. :-)
Also, the food is really pretty good. I think that was the problem with so many of these other Organ- Pizza places ( I was also at the one mentioned in Sacramento) At OSP, the big 32' Diaphone is in the window out in front of the place. I will tell you one tip, though. If you go earlier in the evening, ( 5:30 or 6:00), it is pretty noisey and the organists generally play loud all of the time. Otherwise, you couldn't hear the organ. Towards about 8:30-9, they start playing the softer and more "serious stuff" which you can hear the beautiful strings, solo reed stops, etc. I got to play on the organ a few years ago when our American Guild of Organists chapter made a "pilgrimage" to see and hear it. It was fun to play! You can very easily spend all evening there. It is "cheap" entertainment!
P.S. I am sorry to be slow to respond to this, I haven't checked this forum lately.