From: Marten van Kerkwijk

Though based on my experience with Quantity, I'd also argue that the more annoying problems are not so much with `ndarray` itself, but rather with the helper functions.

Just to give an alternative view - as another astronomer I would say that concerns about the use of subclassing in Astropy is one of the reasons I rarely use it. To take an example, if I’m relying on the Quantity class to keep track of my units, then if I have an (N,3) array-like of positions in parsecs, that’s just one step away from going through the sausage-machine of scipy.spatial.cKDTree.query (to find distances to neighbours) and my units are toast. That probably sounds stronger than I meant - keeping track of units systematically is neither easy nor unimportant and I have enormous respect for the developers of Astropy and the community they have built around it. Peter Creasey