I don't know Gab. For me as a user, new-to-Stemmit and old to Minds, both seem pretty much the same when it comes to topics or payout. Minds, however, forces you to see other people's boosted posts and has not so good filtering. From creators perspective, I am too new to Stemmit to judge. But I believe both sites can make you some money.

Technology protecting the sites is described by alexandermeta pretty well. If you are afraid of censorship or such, Stemmit should be better choice.