Rated 5 out of 5 stars
This add-on does exactly what it should do -- integrate Pastebin posting with the web browser and in the same simple-but-fully-functional manner of the Pastebin website itself. I'm really surprised this add-on has any ratings below four stars.
Regarding previous negative reviews:
1) "The Pastebin toolbar icon isn't movable..."
I've been able to place the icon anywhere on any toolbar without any problems using Firefox v3.x. I haven't tested it on any of the v4.0 betas, but it doesn't appear to be an issue on any of the stable/non-beta releases of Firefox.
2) "Pastebin posts aren't removable..."
That's simply how the website works (and a post can always be set to expire if you're unsure about it) so I think it's unfair to blame the add-on or give it negative reviews.