Purpose of Media module
The Media Module (2.x) uses the File Entity module. Files become 1st class citizens in your Drupal installation just like a Node or Entity or a variable. A FileEntity can be queried using Views for instance.

IMCE (to my knowledge) is simply a file browser (bridge) for your server compatible  with TinyMCE and I suppose CKeditor now. Files are just files on the system and drupal isn't 100% aware of them and their meta-data.

If you only need to browse files then IMCE has its usages. If you want something more meaningful and integrated with Drupal as a whole look at Media, and maybe like Media Browser Plus.