I just picked up my DTV at the Royal Thai Embassy in Jakarta. I applied with a single medical appointment (dermatologist).
It was a very smooth process. Both at submission and pick up there was no wait time. At submission, the (very friendly) officer checked my documents and I explained a few things around the documents related to my financial situation. Other than that no questions were asked and no further documents were requested.
I submitted my application last Wednesday and was told to come back today. However, the valid from date on the visa is the date I submitted my application. They must have processed it right away. If someone is in a rush, it might pay off to chase them up before the assigned pick up date.
I submitted:
Cover letter explaining my general situation and why I am applying for the visa
Print out of an confirmation email of my medical appointment
Print outs from my bank accounts, an overview and statements going back to January this year.
That's it!