Pros for YouTube:
More well-known than SoundCloud
Ability to make money off of streams (even if through ad revenue)
Unlimited upload capacity, whereas SoundCloud only permits this with premium users
Pros for SoundCloud:
Meant for music
Images and video (which are not my forte) are only optional
Easier to find others' work through groups and playlists
Anyone who reads this, feel free to give your own thoughts which I should pick, or even if I should keep using both.