I've never taken the train in Central or East Java, only from Jakarta to Bandung, many times. Eksekutif Class is okay -- big, fairly comfortable seats. (Note that business/bisnis class is different from executive. Eksekutif is the one you want.)

Trains are reasonably clean, but the age of the cars varies and the stations are gritty. Air conditioning and entertainment volume level can be variable too.

As for smoking, hard to predict. There may be rules and they may or may not be enforced. Indonesians are non-confrontational and if someone decides to smoke in a non-smoking area, it's unlikely that anyone will stop him. Toilets and platforms between cars become defacto "smokers lounges."

Same with seat reservations which are only loosely observed. Other than that you will find people courteous and helpful, and someone will speak English. You'll want to keep an eye on your bags, generally stowed in the overhead racks. Porter service is good.

In general train travel is functional in Java and millions of people use it; however the system isn't as reliable as in other Asian countries like India or Japan. It would be an adventure but I wouldn't count on getting much sleep.

I believe Argo and Bima are express trans-Java routes. I may be wrong here so please double check, but I think Argo is the prefix for several all eksekutif routes and Bima for an overnight (biru malam or blue night train). The names and routes change frequently so it's hard to keep up.

Like everything else in Indonesia, if you ask a question you'll get an answer, but the chance of it being accurate is about 50/50. You may be better off deferring your decision until you get to Yogya.

Did you come across this article from the Jakarta Post? Apparently, the Malioboro Ekspres or Molek, which originates in Yogya will start this year. This would be more reliable than the Gajayaya which originates in Jakarta. http://www.thejakartapost.com/news/2012/03/28/pt-ka-launch-yogyakarta-malang-route.html

marmot, Thanks so much for your comments. I had not seen any info on the new train from Yogya to Malang. That is good news.

On seat 61, here is the info on Indonesian trains I found: www.seat61.com/Indonesia.htm You can see the photos (interior and exterior) of an Argo train, and I'm still not clear if it is a designation for a particular kind of route or whether it is a type of train.

We're just researching now. Our plan is to buy our tickets in Yogya once we've decided on which train. SIne we have several days there, it should be no problem to get tickets.

My only experience with Indo trains is from the Prambanan Express last year. It wasn't posh, more like a commuter train (which it is) but it was comfortable enough for the hour-long trip. I saw one or two other trains in the Solo station while I was waiting, and on the whole they looked a lot nicer than the Thai trains I'm used, but I guess that isn't saying much.

All the routes have names and "Argo" is the prefix for express routes that are primarily executive class. Don't expect consistency, though. You may find express routes that are not Argos and Argos that are not all executive. The condition of the individual cars varies by age and use and is also unpredictable.

Thanks, Michael, any comments on smoking on the trains?

Thanks , marmot, the Gajayana is all Eksekutif Class, and is likely the train we'll be taking unless we take the new Malioboro Ekspres.

I have taken an overnight train from Jogja to Malang but it was probably over ten years ago. What I do remember of it was that the air con was so cold I was frozen solid the whole way and my fingers were purple. And as with any overnight train you have to watch your belongings like a hawk. Other than that the train was very good, there were white individual seat covers and it left and arrived on time.

On the smoking issue, there are regulations against it in some places in the country, but not sure if it applies to trains. I frequently do take trains in Central Java and Jakarta and have rarely seen anyone smoke on one.

Thanks, kuluk, that is useful information.

I didn't see anyone smoking on the Prambanan Express, but it's a short trip and it was a crowded train.