You can now download a completely functional 30 day trial version of the newly released AutoCAD 2014.
Take the 28th release of AutoCAD for a test drive with no missing features or strings attached. It has the same DWG and API versions as AutoCAD 2013, so you won't be creating incompatible file issues. You can run it through its paces to decide for yourself if you are going to upgrade or purchase it as a standalone or in a product suite.
Checkout the AutoCAD 2014 Preview Guide to get a overview of some of the new features and changes.