Vantaggi
If you love the arts it is an exciting place to work. There is something magic about working in an active theatre with world class performances. I enjoyed the occasional free tickets to rehearsals (although they are mainly during the work day). It's a gorgeous building, excellent location (easy commute), plus it's small enough company that you can get to know a broad range of people. The Christmas party was always a spectacle.
Svantaggi
Pay is not great. It's not a very diverse workplace (super white) but again I think that is not uncommon for this industry. There's literally no career development here. I can't think of any examples of promotion (in any department) that I am aware of. People tend to stay for years and years in one role and stagnate, so I'd say it's a great place to work for a while (1-2 years) to get some great experience, but don't expect to get a new job title or raise, or even the opportunity to apply, even if others above you leave. They don't seem to ever promote from within, always source new people from outside which is a shame.