If a Firefox plugin does not work or doesn't do what you want it to,
uninstall it or disable it.
Having multiple download managers in Firefox will be trouble, no doubt.

I think you need to more familiar with Firefox to determine it's usefulness.

NetVideoHunter Video Downloader for FF

Has "best available" option, but doesn't seem to be updated frequently enough (people on the respective mozilla page say it didn't download the majority of YT videos for many months; or then has problems with newer FF versions?

Frequent updates or lack of them don't bother me if it works.
The comments are reliable to a point, that point being overall ratings and tips for operations.
And my own experience with the add-on.

I hope you find something that works for you.

I dont know what the competition is like but I use clipconverter (http://www.clipconverter.cc/addon/ or www.clipconverter.cc) for the occasional download with FF and am quite happy with it. It offers addons for:

Install <strong>Firefox Addon</strong>
Install Firefox Addon
(Click 'Allow' at the top bar)

Install <strong>Chrome Addon</strong>
Install Chrome Addon
(See below how to install)

Install <strong>Safari Addon</strong>
Install Safari Addon
(Click 'Open' and 'Install')

Install <strong>Opera Addon</strong>
Install Opera Addon
(Click 'OK' and 'Install')

A downloadable archived copy of Firefox (from the www.portableapps.com website) is normally below 20MByte. This is the plain version, without any plugin/add-on.

I have been using this for almost 2 years now, and only because of the zotero plug-in (and actively using that for doing web-research) my Firefox setup claims 900MByte of room on my hard disk. Around 800MByte is zotero, the rest is Firefox and some other plugins/add-ons. Nowhere near as extreme as in your case.

If storage space is a concern to your setup , you might want to use cleanup tools. Assuming you don´t already do this, I´ll mention that on the same portableapps website there is also a recent version of crapcleaner, which could help a lot in cleaning out the folders mentioned by 4wd.

This system works well in my Windows setup, where I replaced installed software for their portable version as much as possible.

My afterthought becoming: ... hence the incredible non-professionalism and the sharp colors of the relevant sw here. Otherwise, I'm accustomed to business sw, so the shock seeing vid download / converting sw in action was a heavy one.

Hi Helmut,

I'll say that for what is ultimately a "small amount of dev dollars" there really are gaps in the Utility category of software. I bet it's not the answer you need but it's sounding like you're close to needing to commission something to put in the special features you want.

As for FF portable, you, 4wd, spoke about that version from the beginning; I have to admit I didn't "get" this in time and installed the normal version, but of course, a cache of 50 MB or suche doesn't explain my loss of space.

A default full installation of Firefox sets the disc based cache at 1024MB, (the same as IE seems to be whenever I've done a new install), this is about 950MB too much AFAIAC.

FirefoxPortable has the disc cache set at 0MB, (but not fully disabled), by default.

What I believe Shades is talking about is the Profile folder which contains more permanent data, eg. bookmarks, passwords, addon data, etc.

The FirefoxPortable link I put in above. (on my server), differs from the official one in the points I mention previously - the folder shouldn't get any larger unless you install more addons.

BTW, the homepage I added when it's run is instructions on using BYTubeD with DTA!, (with pictures).

However, the one I like best is called Spacesniffer, which is both free and portable.

Hurray for SpaceSniffer 

I've found the FlashGot extension running under FF (in conjunction with the DownThemAll download manager for some extra capabilities) has yet to fail me grabbing a YouTube (or Vimeo) video. It's all running locally (and AFAIK transparently to the hosting site) so nobody is aware of the fact you're saving. Big plus since some sites will truncate a feed if they detect some of the better known download tools in operation.

Get the youtubecenter plugin,

I have it installed in FF 28.0. It doesn't seem to be there however. How do you use it?

Remember Laura Nyro.

Why that repeated phrase?