I am Mox author and, honestly, I rarely use it. The most important part is to think strongly about what you are mocking and your interfaces (explicit or implicit). Once I do that, I do my best to use plain anonymous functions, modules, or protocols to test it. If you already have this discipline, then Mox only adds “paperwork”.

If you have layers of interfaces, it is worth asking why you need mocking across several layers.

YMMV, of course. As long as you are mocking with care, use whatever floats your boat. :)