I trust Square. One of the founders donates a lot of money in STL and a non-profit he launched is what helped me land my first jobs as a developer. I just don't know how the app works, whereas I do understand how Zelle and PayPal work. I'm trying to figure out if and how they offer buyer protection and just wanted to get a feel for what people think of it. I'm seeing a really great deal on a USA G&L ASAT Z-3 in Plano, Texas. If you're in that area I'll let you know what I'm looking at (I have no problem letting you have it if you have the cash and want it). Problem is the seller is new to PayPal and they put holds on money sent (which I believe because I had this problem with one other person recently when they just opened PayPal).