I was expecting something in the order of minutes. Seeing as I work at a place where full build used to took about three hours on a server. I see how it's not ideal though.
In a typical Javascript workflow, near-instant feedback is the baseline.
I really like how Facebook's Hack has a local file system monitor which incrementally compiles on file changes. I haven't used it yet, but it sounds like a nearly ideal compromise.
Typescript has a command line option for this as well.
As far as I can tell, the language would also support a non-validating mode that would be more or less instantaneous (the transformations it performs are all local, and none of them involve knowledge of the types involved).