Firefox seems more responsive with uBlock compared to Adblock Plus. It also has more features and better accessibility in certain areas. The interface, however, could use some spit and polish. There's also one feature missing that's an absolute must have.
First, I wish the button icons in the toolbar popup panel could optionally be swapped for abbreviated text labels. Repetitive mouse hovering for tool tips is a colossal pain in the ass. For my money, it's the single most frustrating thing about software interfaces concerned more with sleekness than usability. Some are so encumbered with mystery icons that you end up playing the board game Memory every time you open them. In uBlock, the toolbar foldout panel could be expanded to accommodate wide buttons. Size doesn't matter anyway since it steals focus.
The other feature missing from uBlock is sadly a deal breaker for me. Maybe I've overlooked something, but I can't find any functionality or support for keyboard shortcuts. This is a HUGE accessibility handicap. I need to be able to hover over any page element and send it to the phantom zone with one fell keystroke (or combination). Adblock Plus used to provide this ability, but uBlock only offers a context menu option, and even then just to initiate the blocking sequence. It's no substitute for a one-and-done rapid-fire keyboard shortcut solution, especially if you use the living hell out of it.
Even with my perceived limitations, the speed gain with uBlock compared to Adblock Plus is definitely noticeable and well worth the cost of the brutal learning curve associated with all the filters. Beginners should expect to do a whole lot of reading to make sense of them, but anyone who needs to preserve bandwidth and immunize against background leeching they never knew existed while also giving Firefox a shot of high octane fuel, test driving uBlock should be a foregone conclusion.