Great to see the Hashicorp vision coming together across the individual tools! We are huge fans of Vagrant ( https://github.com/snowplow/dev-environment ) and Packer at Snowplow. Just starting to experiment with Serf and potentially Consul. The "Hashicorp way" of devops has really helped us too. The only real weakness I see in the stack is Terraform. The elephant in the room is CloudFormation, and being built in Gola…
IMO the best of the AWS libs is github.com/bmizerany/aws4. It only wraps the auth, the API and results are up to you. This requires more work but means you never have to worry about the lib keeping up with the API. With something that moves as fast as AWS this is great.