Hi, sorry for long response time, I’ve been totally away from medium.
Concerning your question, frankly I didn’t have a chance to try usergrid in real project conditions. But I have to admit that know I consider userfrid to be completely useless.
Almost any real-life project would require some custom business logic that userfrid-like BaaS services have no room for.
Using BaaS you will have to place it on client-side that is error-prone and will turn into fat clients. One day the project will definitely end up with unmaintainable zoopark of client versions.
So my conclusion is to have custom backend. BTW, that’s not so complicated to code, as it used to seem to me.