I've been using Vagrant/Virtual to run Ubuntu LTS for my Javascript dev env. Does it make sense switch to CoreOS? I generally run it as a headless server. No X-windows or GUI needed.
Stay for now on Ubuntu. Personally I would be sceptical for some time before the hype of a new Linux settles down.
Ubuntu is proven for many many years and stands on the shoulders of giants named Debian. CoreOS is a pretty new shiny product which still needs to prove itself.
