Despite being one of the best adblockers, uBO is a small but noticeable performance hit to me- it's still worth it though. Nature of the beast I suspect.
Can you be more specific about "noticeable performance hit"? A whole lot of work has been done to avoid "noticeable performance hit", so I would be curious about a reproducible case for this to find out the cause.
I will attempt to come up with a test case. Mostly I just noticed when resetting Firefox or with a new install, "hey this is snappier than usual" until I install uBO. Not sure if it's resources, UI responsiveness, or rendering speed. uBO is awesome, and I appreciate all the work.
I thought you had hard data backing up your claim. Frankly I am quite skeptical at any unspecific "noticeable performance hit" claim. uBO's overhead is typically in the low milliseconds range, which amount to noise-level overhead really when compared to everything else occurring at page download/rendering time.
Well, I went straight to Facebook as it's got a lot of ads, and disabling uBO does appear to speed up the "long tail" load of FB.
I'm not complaining, and if you're confident in your overhead times feel free to disregard. Just unscientific observations. I still love uBO and use it across the board.