I have selected specific ou's to sync for user profiles and added exclusion filters. After an initial full sync I have gone back and un-ticked some OU's. Performed a full sync but the profiles are still in SP.
The Sharepoint AD Import when initiated through a full/incremental import will not actually delete profiles no longer matching the criteria provided. Full import will detect the user is not getting imported and marks the field 'IsImported' to 0 on DNLookup table in Profile DB for that user. This will be eventually cleaned up by MySiteCleanUp Job (default runs hourly). The timer job will immediately remove user profiles marked for deletion (by FIM Synchronization) and will also potentially remove a Mysite associated with a user profile.
Here's a thorough post with all situations under which UPSA and profile deletion works (It says 2010 but still valid for 2013): http://platinumdogs.me/2012/10/18/sharepoint-demystifying-user-profile-deletion-mysite-removal/