We attended last December for La Traviata. Same place you mention here. I enjoyed it, my 16 year old daughter did not, but only because she decided opera is not for her.
I've been to SF Opera for a few performances over the years, and this was an interesting opera evening of a different kind. It was nice to have the singers up close and intimate.
The "palace" is a bit run down, but in a way it adds to the charm. You start off in one room, have a break with refreshments, move to another, etc. Each room fits to what scene is being performed. There are somewhat comfortable chairs arranged in each room. It's not a very large crowd, so makes it even more intimate. Musicians move from room to room as well.
I didn't have any problems finding it, but we left early just in case.
I felt it was worth it. We are going back to Venice this week, and I would have gone again but since the kiddo does not want to, we will be doing something else.