Very cool! I like the visualizations a lot. Did you try to get an interpretation for what each quantized vector dimension means (have just skimmed, not read)?

Also, I am curious why you chose to go straight to publishing on Arxiv? I am actually also in CS224N right now and have a project me and my collaborator feel is publication worthy, but our plan is to go the normal route of submitting to a conference and only putting it on Arxiv after the review process (though our code is open source, so now that I think about it maybe that's not that useful a plan...).