So with Crouton, you don't actually dual boot. It's more like a VM, but it uses the same kernel that Chrome OS uses, so it's more like Docker than Virtualbox.

I have a cheap 11" Acer C720 and I probably use it more than my Macbook Pro. I have command line only Ubuntu installed, and the result is a tab I can open to have a full linux shell, much like how you would use a macbook. For all intents and purposes, it's the same OS, but it's not.

A few things I particularly like are battery like (maybe 8 hours?), no fans, matte screen, and macbook like keyboard and trackpad. Also Chrome OS maps the F1/F2 keys to forward/backward keys in Chrome, which I use all the time surprisingly.

All in all, I would highly recommend a Chromebook. For development it's great. If you don't want to use Crouton, a linode server you can SSH into is just as good as a macbook really. Now that they will be able to run all Android apps, it's even more tempting.