What Chromebook that isn't a Pixel should I get my parents?

Out of nowhere the other day, I got an email from my dad saying he was thinking about buying a Chromebook. I've only ever used the Samsung Chromebook - and that I borrowed from a friend for a weekend. I put together this compare list for the Acer C720 and HP CB11. Anything that I should add? Anybody got a recommendation?

http://www.theverge.com/products/compare/7411/7376

Thanks!