Thanks for the tip, Westtipp. I hadn't realised she's coming here again next year. I missed her last time for some reason, but I've now booked my seat for next May.
Yes, I love the ROH, even more after the recent renovation. The public areas are now brighter and more welcoming. For a while, they had Maria Callas' costume, wig and props from Zefferelli's production of Tosca on display on the ground floor, but they've now been replaced. Fascinating to see, though. Tito Gobbi's costume was nearby.