GP 2013 R2’s Approval Workflow is really very complete for 1.0 re-release. There’s also a lot more coming in the 2015 version. Something that is on the radar, but not yet on the build schedule is the ability to email attachments with the approval request. For example, if you want email a quote to support the approval of a requisition, you can’t do that. You can attach a quote to a requisition, but it doesn’t flow with the email.
If you’d like to see this functionality in a future version of GP, head on over to MS Connect and vote for it at: