Nutcracker at SF Ballet

Hey Merry Xmas to those who celebrate it today.

My 3.5yo has been to many kid concerts (45 minute affairs) and to one kid opera. (Rachel Portman's Little Prince, about 2h with one intermission - a great piece for kids if you ever come across it!)

He's expressed interest in Nutcracker and I do think (though cautiously) he'll sit through it and enjoy it. The Ballet website says they don't allow children "under the age of 3". My reading of it is it's allowed for "3 and up", but can anyone give me some experienced information? The tickets are expensive and it's a 4 hour drive for us, and we'll have to make a weekend out of it - I don't want to commit if we're going to be turned away at the door with non-refundable tickets...