The Magic Castle is a fantastic night out. Kitch magic shows, fun bars, great ambience and historical artefacts.
It isn't a great restaurant, but the dining forms part of the fun of the evening. Plan to spend 4/5 hours minimum there. See every magic show, visit every room.
The dining room is packed too tight and the walkway to the theater is right through the restaurant which can get very busy so don't expect a quiet romantic meal.
Food is typical tourist cuisine. Overpriced and unloved. Like wedding food it appears to be mass produced at times. Steak is safest. Service is good but lacks elegance.
But you aren't coming for the cuisine, you're coming for the MAGIC, which can feel dated at times, but go with it and you'll have FUN.