How to know whether it's worth it to replace open source drivers installed by default with proprietary ones. Are there any benchmarks? Major known issues summaries. I don't mean 'at the time of writing this post'. I mean an up-to-date status on how the drivers compare.
This page https://help.ubuntu.com/community/BinaryDriverHowto/ certainly doesn't do much on the matter, nor it even mentions Intel.
I've just learned there is no Intel proprietary driver because they made their drivers open source https://askubuntu.com/a/17395/29347