My post-pub, pre-print, pro-bono review of this paper is: accept without revisions.
This paper presents a very useful set of tools for the Drosophila CRISPR community, all of which are immediately made publicly available, with detailed protocols - a model for how such work should be presented! In particular, I believe that pCFD5 plasmid for expressing multiple gRNAs will be very useful to many in the field, as well as the ability to do tissue-specific knock-outs using the UAS:gRNA plasmid. I hope that such robust tissue-specific knockouts are generally applicable for other genes.
I was also happy to see that Port & Bullock published their work on the Cpf1 system, showing that while it is functional in flies, it does not appear to be quite as robust as Cas9, and has a relatively high failure rate (which I have also observed myself). I am glad to see such "negative results" (well, not exactly negative) made public, as this will undoubtedly save others much time.