Glad you had a great trip. It's true about the Javanese language rarely spoken but mostly with folks within the countryside (also depending on the region).
My wife is Indonesian from Bojonegoro and she speak both Indonesian and Javanese. It was interested because when we spent time in the city areas, she spoke Indonesian but in the countryside and amongst the elders, she only spoke Javanese.
We were there a few years ago and it was simply an amazing experience. We're looking forward to going back soon but only gripe is basically the long flight there. It's, as you know, a 20 something hour flight.