I've also spent a small amount of time using the bundled office suite 'LibreOffice' which comprises of Writer, Calc, Impress (presentation tool), Base, Draw and Math (an application designed for creating and editing mathematical formulae). Each application seems feature packed and was quite happy opening my Microsoft Office created documents. But as I tend to rely on Google Docs for most of my day-to-day productivity I don't think I will have much use for an office package on my install. If you want a review of LibreOffice then try here.
Oh one final point, I said when I installed Ubuntu that the speed of install was helped due to the lack of a million Windows updates... Well Linux/Ubuntu isn't excluded from such chores (362 updates! See right). At least it was happy to run in the background and didn't impede my use of my laptop. Also it updated everything that was installed through the Ubuntu Software Centre (or at least seemed to). That is one benefit of the centralised software repository.