"Switching to the new mode might take some getting used to though, so if you think your fonts are suddenly fat, fuzzy or weird, give your brain some time to adjust." This is true, and IMO it's the reason font rendering is much less important than people think. When I got a new pair of glasses I disabled font anti-aliasing to make the edges as sharp as possible. I did this so I could more quickly learn to focus my eye…
Though beware of Windows' ClearType, which seems to do a bad job on hidpi: it renders very thin glyphs, and the glyph width discontinuously jumps from 1px to 2px when you change font size. It tries way too hard to snap to pixels. OS X and freetype (tested: 2.6) do a much better job on hidpi.