The original scores assigned by the reviewers had a large variance. Some of the problems raised by the reviewers were however addressed in the rebuttal and one reviewer raised his score. After the discussion period, the reviewers agree that the paper makes some novel contributions, arguably novel for some reviewers. They also agree that the clarity of the paper should be improved. Overall, the topic addressed is an important one and it seems that the authors could improve the presentation for the final version, justifying acceptance as a poster.