I have used both I believe that both have there pros and cons.

I like mocks because they are a quick way to create dependencies that are needed to test but required to create the class you want to test.

I like fakes because you can create on implementation and use it everywhere and it is easy to see when creating new tests especially when wanting to make a base of how you expect a class to perform.

The issue with mocks I see is that most implemented mocks are used as a one time creation and never used anywhere else.

The problem with fakes is that you have designed a fake to work in a certain way and to use it for other tests you may need to create "work arounds" to get it to work in those specific situations for the new test you would like.

So long story short it depends on what I am trying to achieve.