I wonder if a change to general font rendering have also been made
Using Chrome, all of the fonts started seeming thin to me
I've tried various FontSmoothing settings, I reset Chrome every time I make a change, I used to be able to differentiate different FontSmoothing levels, yet with El Capitan, I can't differentiate them
I also inspect the fonts with "Zoom It" / a loupe app, all of the FontSmoothing levels seem the same, fonts seem thinner, I can't see the retina detail, I can easily see the pixels around characters
Before making the retina upgrade, I had a problem where I couldn't focus to the texts (especially black on white), whenever I looked at texts, my focus went deeper than the screen, it's hard to describe but it's a form of confusion, I even started wondering whether I need a new eye prescription although my eye-exam was fairly recent and thorough - anyway - the retina upgrade prevented this issue previously, crisp fonts prevented the issue, I concluded that it was the font rendering all along
Now with El Capitan, this issue is back
Since the issue isn't quantifiable and I don't have another system to compare things to, I can't verify the issue and summarise the issue well, but overall, not just the system fonts, but I seem to hate the general font rendering too, it seems changed