The singing is good, the acting is good, although one of the star moments appears too be unplanned (near the end of Act II, Lady Jane barges into Bunthorne and sends him sprawling - and then can't control her laughter). It's a live performance in front of an audience at the Sydney Opera House, so accidents like that can't be cut or redone, but this is a comic opera after all, it's supposed to be funny, and Gilbert once told an actor to make a regular feature of a similar accident in the Mikado because the audience loved it so much.
Patience contains some of Sullivan's best music, and Gilbert's work is excellent too. As a satire of the aesthetic movements that were running around in the late 1800s, you will enjoy it more if you understand something about them, but The Complete Annotated Gilbert and Sullivan (available here on Amazon) explains a lot of the refences, and the opera is very funny even if you don't know anything about the Pre-Raphaelites, Oscar Wilde, etc.
The performance sticks very closely to Gilbert's original words, with only a very few lines being cut.
The biggest complaint is the Patience has a weird accent - or she does in the spoken dialogue, it's not so noticeable in any of the songs.