Below are the generic installation instructions and yes it can be done in 20 minutes if you already have spent the time lining up all your ducks in terms of information and pre-requisites
Here is a list of some of the top new features in XenDesktop 7.
Installing your Site on your first XenDesktop 7 Controller
The Prepare Machines and Image allows you to install the new VDA (Virtual Delivery Agent, not to be confused with Virtual Desktop agent used in XenDesktop 5.6 and earlier). The VDA replaces the traditional XenApp install for XenApp servers in all previous versions of XenApp, Presentation Server, Metaframe.
This makes a complete distinction between a controller where you install the full controller software and everything else. Gone are Worker Group Server concepts. Everything else just gets the VDA, be it a Windows Desktop OS, XP and above, or a Server OS, 2008 R2 and above.
(See the License Server Install section below on Installing the License server, as we deselected it earlier for the purposes of this document).
30. The install will commence
Installing an additional controller
As you will no doubt need to provide some HA / Fault Tolerance or just scale out your controller service, here is how to add an additional controller
1. Run the installer as you normally would, click on Start on the Welcome page.
Click on Delivery Controller.
2. Accept the license agreement