I do not use Office products much at all but I've read straightforward CSV and Excel files into OO without problems and Word files seem ok - power users may have a different take on this.
My primary use of MS Office is Access database (used extensively for web sites, not for office use). OO does not like these at all. I cannot find any replacement for Access, although I understand OO database works fine with newly created OO db files. I use MDBviewer to look into Access files but that does not solve anything.