One major issue with Soundcloud is their mobile app. If you listened to your own music on the mobile app, the quality is horrible compared to the Soundcloud on your desktop or laptop. It fools you into believing that there is something wrong with the mastering. You will hear clicks and pops. Makes sharing your music over the aux at a party or friend's place humiliating. Especially if said friends are familiar with audio mastering. Youtube's mobile app does not suffer the same issue.