One of the coolest laptops I have ever used - literally as well. It is powerful enough to keep up in speed with the Pixel, but runs much much cooler and for far longer.
I have switched to using this on a regular basis. And Chrome OS sings on this.
I really wish for a new Pixel with the newer Intels. I must say that Intel has really done a great job with the Haswell series and I am really looking forward to Broadwell as well.
And finally, Chrome OS has matured so quickly so fast. I love using a chromebook as my daily machine for work. It boots up much faster and suspends/comes alive much faster.
And remember that Chrome OS is still not fully optimized.
Hands down, the coolest innovation in the last couple years has to be the 6-week cycle of Chrome and Chrome OS - client software - once a pain to get into a yearly cycle is now auto-updated once every 6 weeks. Kudos!!
I highly recommend the Acer C720, if you are considering a chromebook. A lot of win in this one.