I've seen a lot of interesting tools they're building (e.g. https://launchpad.ne...

I've seen a lot of interesting tools they're building (e.g. https://launchpad.net/scratch, https://launchpad.net/geary), so I almost want to use it, but the OS X mimicry is a huge deterrent. I haven't used it. I did find this though: http://elementaryos.org/docs/human-interface-guidelines