#scichat google docs collaborative lab report: success?

In general, my chemistry students benefit from breaking down a lab report into smaller chunks with multiple deadlines.  Instead of asking them to write a full lab report with hypothesis/procedure/data/analysis in the week after we do a lab, I usually assign the research a few days before, write the hypotheses together before we start, do the graphs together when we finish the procedure, then assign the conclusion for a few days later.

In this lab, the research portion is pretty detailed.  The students need to find out the properties of ionic and covalent compounds, specifically melting point, solubility in water, conductivity, and appearance.  These aren't discussed in our book so it takes a little more than just looking through our notes.  I decided to assign portions of the research to different pods/tables, and have them all add their paragraphs to one google document.

the good:  with the jigsaw approach, students were much more likely to do a thorough job on the part they were assigned.  and I mean a ridiculously thorough job.  I had to ask a few to cut it down so it could be more manageable for their classmates to read.  Each table presented a summary of their research on lab day to get every one caught up on the same page.

Another benefit was finding the students who were not prepared.  If their assigned section was missing, they were clearly unprepared and I asked them to go to the computer lab to prepare their research and come back later when they were ready to perform the experiment.  It wasn't always possible to do this before due to the difficulty of scanning everyone's research for completeness.

the bad:  the google chat side bar.  when I was present in the chat, students used it to ask me silly questions about myself.  I think that came from the novelty of interacting with a teacher in a social media environment.  when I wasn't present, there were reports that students used it to antagonize each other.  something tells me this isn't new behavior for the students being the antagonist, just a new forum where everyone could see it.  

In any case, it's definitely something I'd try again.  I still had students submit their conclusions individually, as that's my primary assessment for this experiment.  In other labs, I sometimes use the graph or the hypothesis as my primary assessment.  I'm also thinking of creating a five-slide presentation template for students to use to quickly summarize and communicate their findings instead of writing a full, formal report.  In that case I create a template and make it able to be viewed, but not edited.  Students can download a fresh copy, add their own data and then share so we can see and compare each group's data.  

How do you use Google Docs in your classroom?  How many contributors/collaborators do you think can effectively work on one document as the same time?