Contentious. That's a good word to describe the reception of iOS 9's ad blocking capabilities thus far. On one side you have the argument that content producers have a right to earn a living from their work, on the other that users are entitled to a level of control over what happens when they visit a website.
Personally I disagree with the concept of preventing ads from displaying, at the same time
understanding why people feel that intrusive and data gobbling downloads are ruining their browsing experience and costing them money (on mobile devices anyway).
Having upgraded my iPhone 6 and iPad Air 2 to iOS 9 and installed some content blockers to see how they work I found browser performance was not particularly improved. Side by side with my second iPhone 6 running iOS 8 there were negligible differences in load times. However, I didn't measure data so that might be the real differentiator here.
I did compare the iOS ad blocker on my iPad with Internet Explorer's TPL on the Surface 3, with illuminating results. Whereas Internet Explorer stripped ads out of the sites I visited without fail, Safari with the content blocker enabled left some in, often all of them.
So the iOS Ad Blocking apocalypse may yet be delayed, however there's no doubt that developers will soon learn how to improve performance of the ad blockers, just as ad networks will learn how to defeat the blockers.
Ultimately there are no real winners. Except for Apple which gets to push users to apps instead of browsers and reaps the ad income delivered in that medium. Needless to say, after completing the tests I have disabled the various blocking engines on my devices.
This debate is going to run and run, I certainly feel the argument is more nuanced than the simple, black and white, publishers are greedy / users want something for nothing.
Where we end up and what sort of web we have when we get there remains to be seen.