@pierregm - the problem with doing `dout=self.view(np.ndarray)[indx]` is that, as mentioned above, this *presumes* that a single item from a subclass can be represented as a `np.float64` scalar. This, however, is false at least for astropy's `Quantity`, where one does need to keep the unit.
Note that the problem is worse for `__setitem__`: the baseclass may not allow one to set parts to just anything, it may need to check that, e.g., the data put in has the same class (or, for `Quantity`, that the units are consistent, and convert if necessary).