Is there any reason to use this over AIO Sidebar? Rated 1 out of 5 stars

I've used All In One Sidebar, and besides not wasting the more precious vertical space, it's on the side.
1. As far as I know, there's nothing this can do that AIO Sidebar can't.
2. There's a huge load of things AIO Sidebar CAN do, this doesn't - including a larger variety of in-browser about:* pages.
3. There's a mode to make stuff fit better in narrow sidebar - this makes managing bookmarks, about:config, etc. and reading normally wide pages.
4. AIOS has the ability to move what's on sidebar on the main area, and the other way if wanted - yes, that does mean you can place a webpage you have open into the sidebar; I've found it particulary helpful when I wanted to keep search results visible, and then open link(s) from it.
Here AIOS can use "fit-to-width" mechanism that some addons support (1280x1024 is nowdays sometimes too narrow, and I often don't keep browser even horizontally totally maximized), and which in unfortunately uncommon, but still found in many mobile browsers too (UC kinda seems to force it, which only makes me wish it was an option when it fails to keep everything visible). Oh, such addons are golden with sidebars too - imagine I'm using 480px wide sidebar (usually only 300px, but even then it happens), with browser on my FullHD TV this time maximized, and the damn page is made so that it uses javascript or CSS to force it as 100% of the *window's* width - not 100% of the document area, like any sane one does - yet most of the content is inside a dive that barely uses 5th of that space - because of sidebar, part of thet div in the right border is off the visible area. Surely the auther made sure the document's overflow CSS declarations just cut the non-visible part, and in no chance is the page allowed to become horizontally scrollable - I don't understand why that's possible, as if the page should become horizontally scrollable, it's because there's stuff that didn't fit on view. "I got an idea, let's disable users ability to scroll to see it, let's not design our page to fit the stuff on view-area, and if all else fails use wrapping on overflow, and let the user scroll if needed.
That's the craziest example, but an addon with "fit to width" is really nice then. There's one I'm looking, I had it once as I had a netbook with 1024x800 screen (WTF, used to be that 640x480 could show any page - and no page yet has content that wouldn't - I design my pages desktop-targetted design with the fact that 640px is wide enough to have surrounding sidebars and content in the middle, with that in mind I do make use of the fact that there is usually at least 1024px wide screens unless it's a handheld, and use that. It's called gracefully degrading webpage - mine always also works without javascript, especially AJAX, if it has to.
But when on 1920px FullHD a simple zooming (I use "zoom text only" - and I wish it left the CSS margin and padding values, div width's, etc. alone too, not just pictures, but that seems random. But when zooming font to 150% causes the fifth of page go over border, I love that addon - I have to re-find it, because it can usually re-fit the page even without changing my zoom back smaller.

But I'm rambling about something else than this addon vs. AIOS - anyway, there's no equivalent to "fit-to-width" or anything that can help with massive reduction of vertical space - which has become smaller in many cases after 19:6 became the standard. I should have at least 1024px vertical resolution on my laptop, and more horizontal instead of the same optimal 1280px width and ridiculous 786px vertical - I had that on my desktop PC in 1997!

This review is for a previous version of the add-on (0.3.4). 

A Hidden Gem! Rated 4 out of 5 stars

This is an amazingly useful extension, and the functionality should be included in Firefox by default.

If you move the toolbar button to the Panel Menu (aka hamburger menu), most of the functionality relies on the menu bar. This is not ideal, as the menu bar is hidden by default. The toolbar button does not work properly when moved into the Panel Menu (there is no drop-down list to select which page to show), and this needs to be fixed.

Also, the toolbar icon itself needs improvement, as it is just a blank page. It also does not differentiate between on and off states, which also needs to be fixed.

Adding a 'Close' button to the bottom pane would be extremely useful, and I hope the developer adds one.

The instructions are a little unclear, as they specify that the user can select 'about:blank' to close the bottom pane, but there is no such option. Going to 'about:blank' does not close the bottom pane either. Selecting 'show a blank page' is the only option to close the bottom pane, but it is a little misleading. Instead, perhaps 'Close bottom pane' would be a better choice.

The extension does not remember its state when restarting the browser. It would be ideal if there are three possibilities: always start with the bottom pane disabled, always start with the bottom pane enabled, or start with the bottom pane in the same state as when the user closed Firefox.

It's a wonderful extension, which hopefully will see improvements!

The name of the extension is not reflective of what the extension performs, which makes it harder for Firefox users to find.

I've added it to my Hidden Gems collection to try to help!

This review is for a previous version of the add-on (0.3.4). 

Rated 3 out of 5 stars

Nice idea but the toolbar button for using it keeps disappearing without a trace, meaning that you can't find it in the customize window at all. Sometimes it might come back for a short while, only to be gone again soon afterwards (FF 26). Some other restartless add-ons display the same behaviour, but at least one can find the button and reinstate it in the toolbar.

This review is for a previous version of the add-on (0.2.6.1-signed). 

Rated 5 out of 5 stars

neat add-on, excellent idea.

This review is for a previous version of the add-on (0.2.1.1-signed). 

Rated 5 out of 5 stars

it should be better if it opens the panel on a new tab, but it has been very good now, five from me.

This review is for a previous version of the add-on (0.2.1.1-signed). 

Rated 5 out of 5 stars

Great start! a keyboard shortcut would be wonderful:)

This review is for a previous version of the add-on (0.2.1.1-signed).