A few highlights:
- New system font: San Francisco
- Improved Mission Control.
- System Integrity Protection. Means apps like TotalFinder won’t work without a tweak. Bummer.
- Responsive Design mode in Safari. Cool for us developers!
So do they recommend you upgrade? Most certainly, but this quote sums up the differences between El Capitan and Yosemite:
Almost all of El Capitan’s updates are aimed at detail-oriented power users who are intimately familiar with the platform and its apps.