They had a really big bezel, so the current 13" MacBook Air is barely any bigger than the 11" MacBook Air:
- It's 0.5cm thinner
- It's 0.41cm wider
- It's 2.3cm deeper
- It's 200g heavier
The aspect ratio on the 11" model was kind of weird too, a lot of apps would barely fit. But a retina screen would help there - just make everything smaller.