[bryanrasmussen]

whereas I think in common usage text is anything written and manuscript is a subset of document.

Although manuscript in pre-computer days generally meant something handwritten, nowadays I guess you can turn in a manuscript that was written on the computer so not exactly the same.

[fiddlerwoaroof]

I think this is right, although I think the connotations of “text” are a bit more abstract in common usage than “manuscript”.