Since you specified "Proper," this usually refers to a specific release group (often tied to scene releases where a previous version was flawed) or a high-quality web-DL/Blu-ray rip that includes multiple audio tracks. Foo Fighters Greatest Hits Full Album Download
Here is a proper review breakdown. If you are downloading a "Proper" 720p Dual Audio release, here is what you should expect regarding technical specs: Xev Bellringer Incestflix
Reviewing the of The Hangover in 720p Dual Audio requires looking at two different aspects: the quality of the specific file/release, and the quality of the movie itself.
A bachelor party goes wrong. Three groomsmen (Bradley Cooper, Ed Helms, Zach Galifianakis) wake up in a trashed Vegas hotel suite with no memory of the night before, a tiger in the bathroom, a missing tooth, and—most importantly—a missing groom. They must retrace their steps to find him before the wedding.