BEAUTIFUL! I fell in love with this place as soon as I read about it online. Once I got there it was more than what I expected.
Even if you're not into history, this is a must see.
You can do the tour with or without the audio guide. There are signs in each part of the castle telling you what each room was used for. The Library is one of my favorite parts - now it's used for events, and I am totally jealous of everyone that gets to go to one of them.
Being there you just wish you could have been part of that time at least for a day, see how every day life would have been walking through those impressive halls, beautiful rooms, gardens... You can even walk to the stables.
We spent about 2 hours there, just admiring it all.
Again, a beautiful place, definitely worth adding this to your Toronto tour.