The paper studies distributed matrix factorization problems. It takes the view that distributed (sub)gradient descent relates to a regularized version of the original optimization problem, and then shows that stationary points of the distributed matrix completion problem satisfy the consensus constraint. While the significance of the paper caused some discussions, the reviewers remained mostly positive in the final assessment, resulting in a narrow accept decision. We hope the suggested changes and comments help improve the paper for the camera ready version, in particular, this concerns the clarity of contributions, related work on primal-dual and gossip methods as mentioned e.g. by Reviewer 3 and other comments by the reviewers.