I have found in my world it is easy to setup a test database (we use sqlite!) and the file system is fast enough (I have code to force using a different directory for files). I have been playing with starting a dbus server on a different port in my tests and then starting the real server to test against (with mixed results - I need a better way to know when dbus is running). I have had great success by writing a fake for one service that is painful - the fake tracks the information I really care about and so lets me query on things that matter not what the function signature was.

I'm not arguing that mocks don't have their place. However I have found that by declaring I won't use them at all I overall come up with better solutions and thus better tests.