I recommend to not use it with Firefox Mobile. It slowdowns firefox mobile a lot, takes about 10s to load a page. After removed it, it is day and night. Now using uBlock Origin. No impact on perf AFAIK
Thanks for your feedback! Can you let us know what device and operating system you were using when these issues occurred. We'd like to investigate this further and work on a resolution. We look forward to your follow up via firstname.lastname@example.org.