Garuda generally are not that bad (YOG crash aside), and I would not be too worried flying with them. Maintenance is supposedly outsourced to LH technicians.
For Adam Air to have been promoted to group 2 and not suspended does beggar belief. Or not, given KKN.
I was in Jakarta last week having dinner with a friend who works as a loss adjuster there and he was seriously contemplating using AA to fly somewhere to do a survey, hopefully I dissuaded him!!