Ask HN: A high-value paid developer training?

So far I have just picked up books or learning projects and that worked out pretty well for me.

This year, my employer offers a handsome training budget.

I find most of paid trainings not worth it for a senior developer (compared to self-study approach which I prefer).

Have you attended a paid training which is expensive but well worth the money? What did you like about it (compared to just going through a book on the same topic)?