There is a nice review of Apache OpenOffice in the German computer magazine c't. (We don't have this in the US, but it appears to be similar to our PC Magazine.) Of course, it has the obligatory comparison with LibreOffice, and after detailed analysis of the pros and cons of each the article concludes with:
"Thus, the advantages [of LibreOffice] are restricted to smaller modifications. Fundamental innovations such as the Sidebar the developers have only copied, from OpenOffice. Because of this it makes no essential difference which of the two packages you use for everyday tasks. Ultimately the OpenOffice package wins, because its developers seem to add new features only when they are running reliably - as you would expect from professional developers."
I tend to agree. It comes down to quality, something I'm quite passionate about. Although LibreOffice can (and does) copy code from Apache OpenOffice, as it is entitled to by the license, it can never copy the quality unless it copies the whole, since quality is holistic and is not something you will achieve by cherry picking individual files. Quality comes from the totality of decisions that determine what is released.