Rated 4 out of 5 stars

A bit buggy. Some files which includes "-" symbol causes the download to fail. An example: http://www.download.hr/go.php?file=w6775&code=m1a4l3q7y6q7q6y0b0v6 (Non-direct link: http://www.download.hr/download-k-lite-codec-pack-update.html). If you click Run option, download will finish instantly and will open a black screen that automatically closes in about 2-3 secs. If you click Save, then the download will work as expected, beacause this is native from Firefox.
I'm now using Firefox 39.0 es_es on Windows 7 32 bit ServP1 Spanish

This review is for a previous version of the add-on (4.0.1). 

Rated 4 out of 5 stars

It's so good, but there is a bug in v. 4.0.0, beacause the plugin doesn´t create the preference of where to save files before running it.

This review is for a previous version of the add-on (4.0.0.1-signed). 

That's not a bug. The preference is only needed if you want to change the location yourself. :)