What are the downsides of changing a map service to MIME only? The developer summit perf video says that it is faster and scales better just using MIME.
What things break from not having the image written to disk if anything?
List of broken things:
I'm also noticing when setting layer definitions the js api posts if the get request is too long and tries to send back the url instead of the mime type. if it's mime only the url json prop is empty.
With arcobjects, if you try doing IMapServerLayout.ExportLayout the url property isn't set but the mimeData property is set.