Hmm.. A week ago was my second experience having a trip by economic class locomotive. I and my friend, Japeb, were going to Yogya from Surabaya by Sri Tandjung. The ticket only Rp 30.000,. It is much cheaper than business class, Rp 105.000. They are alike. No standing passanger anymore. The facilities are same : fan, toilet, and comfortable seat.
I think the different is only time duration. You should more patient on economic class. They arrive later than business and executive class.