Config is a subclass of dict, so it does a real comparison:

```python
In [4]: from IPython.config import Config
In [5]: c1 = Config(A={'trait' : 'value'})
In [6]: c2 = Config()
In [7]: c2.A.trait = 'value'
In [8]: c2 == c1
Out[8]: True
In [9]: c2.A.other = 5
In [10]: c2 == c1
Out[10]: False
```