Mixed bag from what I'm seeing:
Patreon looks easier to use for me, but they have a lovely track record of policing artists' work outside of the platform because their masters above have problems with potentially being known for keeping artists that do questionable work onboard.
SubscribeStar just feels like the Mixer to Patreon's Twitch, but that's my opinion, but from what others say, at least they don't harass you for what you post outside of their platform. Yet.