At the risk of being that guy who mistakes his anecdote for a datum, I've found the bigger ad-blocking extensions to have a larger performance impact - simply because they're evaluating large regex based block lists on each request.

That said - that's my choice, I don't have to use those extensions, but the gain is, to my mind, worth the pain. I really don't like the patronising "we know what's best for you" attitude of the Chrome developers - especially because what they came up with as being "best for us" is also best for Google.