:) Rated 4 out of 5 stars

Thanks for the information. In fact, a detailed info :)

I believe, since Mozilla is an open source, there has to be an alternate to your implementation.

However, I'm increasing your star rating:
1 for the very good information
1 for the very good implementation
1 more, appreciating, expecting you will figure out an alternate.

;) Cheers !!!

This review is for a previous version of the add-on (1.0.4). 

:)

Ok, thank you, I want just to inform you after reading more about it on Bugzilla and mozillazine forums that this is indeed a Firefox bug present for years now. This cannot be fixed inside an add-on but must be fixed inside Firefox. If you have time you can read about it here:

https://bugzilla.mozilla.org/show_bug.cgi?id=401213
http://forums.mozillazine.org/viewtopic.php?f=18&t=706855

Pixelation of scroll bar Rated 1 out of 5 stars

Though it is not a bug, it is a bad customer experience. Who would really need even a scroll bar to zoom out/zoom in? On the contrary, there is a pixelation which makes it look bad.
I have no idea on this. I would appreciate if you can explain to me any of its benefits. :)

This review is for a previous version of the add-on (1.0.4). 

You can contact me via email to discuss such things, no need to post "one-star" ratings for what is not a (real) bug. ;-)

What exactly do you want to have explained?
Mozilla decided images have to be zoomed too when Firefox zoom settings are used. To restyle scrollbars Mozillas default ones have to be disabled and replaced with images. Unfortunately they are affected by the zoom feature of Firefox (because they are images now) and there is nothing that can be done about it, except to disable the "zoom images option" in Firefox zoom settings.

I know images can look very ugly when they were stretched and nobody needs scrollbars to be zoomed but this is how things work. Its not my dicision ;-).