без включенного расширения нагрузка на процессор браузера около 3%,после включения 35-50

As per the Wikipedia article: https://en.wikipedia.org/wiki/Stylish is owned by an AD COMPANY RECORDING YOUR BROWSING HISTORY! (Use the community created STYLUS addon instead, which does not collect anything)

Doesn't work. I created a style for a website and gave it the URL. It says it's installed for that site but doesn't change anything. If I follow the instructions on github "Applying styles to specific sites" I get "unsupported rule". The website is filled with broken links and pages loading with errors, so you can't find any information. Total waste of my time, uninstalling.

Used to be good, now it absolutely SUCKS

The "installed" panel is a trainwreck, the only thing that it displays correctly is the number of installed styles for the current page. Some of them are always missing from the list (often enabled ones) and some from unrelated pages are visible. If I close and re-open the popup the list changes so it can't possibly be a case of too URL filters.

Malware, do not install if you want to keep your data secure!

I didn't install this ! It was installed by some devious means I am not aware of. I'm reporting this to Mozilla.

STOP: PRIVACY WARNING!

Install STYLUS instead.

This extension, Stylish, was once the industry standard, but it is now malware. STYLUS is maintained by an active and friendly community of developers, and does not send your browsing information to privacy thieves.

Super slow and doesn't work properly.

DO NOT USE. Steals your browswer history. See https://robertheaton.com/2018/07/02/stylish-browser-extension-steals-your-internet-history/

I loved this extension before, but now with this new version, it's a crap:
On Firefox Quantum it give an huge CPU usage...
So with Quatum, it is better to use Stylus.

On Waterfox Classic 56.3 (my principal browser):
I use an older version with an userscript to edit my userstyles easily and here that's my better solution.

I wish I could give it zero. Widget loads, I select content and download themes. I even fix coding errors in the themes themselves, and yet Stylish constantly tells me I have no themes to use and I should install some when I open the menu.

Да пошла ты на хуй с таким отношениям. Даже ошибку с БД не может исправить, приходится ручками искать и по форумам лазить. А знаете почему именно по форумам? Так эти долбаёбы высрали дополнение на лису, но документацию оставили к гугл хром. Въебал бы за такое отношение.