I've not really played much with chefspec in favor of test kitchen, any major reason to go this way?

My understanding, as I've not implemented test-kitchen are integration tests while chefspec are unit tests. While test-kitchen exercises against an actual OS, chefspec tests converged recipes against fixtures. My understanding is that community cookbook guidelines will be requiring both as we move forward.

I think of test-kitchen as more analogous to Selenium browser tests.

There are no community cookbook guidelines as Opscode's policies hold no sway here :-) The problem I've had with chefspec (and why I don't use it personally) is that it mocks out a lot of Chef internally, which fails with Poise-style cookbooks and their multi-level resource structure.

You can create more complex build matrixes that would effectively exercise both test-kitchen and chefspec across multiple platforms and Rubies, but it would require a bit more effort in the build setup.

test-kitchen is a little different since it doesn't use the local system at all, it just spins up Rackspace instances and talks to them via SSH :-) This looks good for now though, and having a template for a hybrid chefspec/TK travis run is something I want to do anyway.

Let me know if you need/want any help/input. I need to add test-kitchen to my own cookbooks and am keen to establish a sane setup.