Was just waylaid in debugging an issue because I thought I was dealing with two-tuples but it was actually a GridQubit. Their str representation is indistinguishable. I suggest adding a subtle hint that it's different.

The closest analogy I can think of is the difference between a python list and a numpy array

In[3]: l = [1, 2, 3]
In[4]: print(l)
[1, 2, 3]
In[5]: print(np.asarray(l))
[1 2 3]