Does not block all ads.
For example:
ffmovies opens pop up ads automatically when clicking a movie, something Ublock Origin has no problem blocking automatically.

Some sites have inappropriately sized blank white spaces from where the ad was.

Slows firefox...

When it works, it works. Unfortunately it's missing crucial features, like

- undoing latest blocking action.
- listing ALL manually added filters (only shows a few dozen and then the list cuts off).
- search function for "Add Your Own Filters" in order to remove an item from the list you accidentally blocked, which means you need to completely reset the addon and start from the very beginning.
- keeps redownloading foreign language filters that I've disabled AND deleted. It's annoying.
- the Adblocker menu stays open when you click "Block Element" (whereas it should disappear automatically), and blocking box is often hindered by the annoying Selection Mode popup.

I've reported these before to the support email but was ignored. Doesn't really encourage me to donate when maker is oblivious to feedback.

It seems to make my laptop somewhat slower. I guess that is a small price to pay to not see the adds.

No bloquea los anuncios de openload.

Used your "AdBlocker"for over 9 years ! You make using my computer a Total Joy !

Good ad blocker except it gives you pop-ups advertising itself. Block those ads too!

Great add on
Dios Enterprises

It blocks ads and is unobtrusive, but when enabled, there is a very noticeable and distracting flicker when loading different views in a website...

slooow! slower than adblock plus or ublock origin.

Still the best.

No whitelisting tube channels.... omg

Eliminates probably 85% of ads. THat's great. It also blasted me with a huge popup asking for a review. A subtle email would have garnered them a much better rating.

super tool

まあまあ

The interface of Adblocker Ultimate has changed with the latest update. Clicking on the button in a Firefox window gives some options, that don't make sense and some don't work. Also an ABPVN list has been added to the default filter list with no explanation as to what it is. This together with the sudden change of layout of the extension has forced me to remove it. What is going on here ?

slowing youtube.

It did not remove Yahoo Mail ad banner! Would have donated otherwise.

++++

For some time I could not understand why the sites are not loaded, all the tabs stop working at once, as if the Internet was disconnected, this does not happen often, but as hangs and a few minutes have to wait, by exception found that the blocker is to blame...