Here's how you fix the downloads.

[Anonymous]

The Fix: When you have FF set to prompt.

Single file: If I'm on a page and I choose to DL one file, bring up the DL box, which defaults to the previous DL folder.  If I change the folder, that becomes the new default (just as it still works today).  I click Save (or hit Enter), done.

Multiple files: If I select more than one file to DL, bring up a dialog box which asks if I want to open the file or save it.  Add a check box which says 'Do this action for all files in this download.'.  If I check that box and I choose open, then without any additional prompts or dialog boxes, open all of the files.  If I check that box and I choose Save, open one Save location dialog box, I hit Enter and ALL files save to that location without any additional prompts.

The 'Do this action for all files in this download.' means that the choice is ONLY for the currently selected files. It is not a sticky setting. If the user doesn't check the box, prompt them for every single file. Voila problems solved. 

I think you designers can figure out the rest.

History: You guys tried this, what was it 10+ years ago?  Where you tried to force DLs to a location based on the source domain.  (IIRC it was because your developers wanted to save all of their illegally DLd game files to a single place).  It failed miserably then, just like this new change of yours is failing again now.  Just because files come from the same domain doesn't mean I want them saved in the same place, any more than files being of the same type (.jpg, .pdf, .xls) means that I want each of those file types in saved the same place.  Context is in the content and intent, not the file type or source.