Excel had a pretty nasty regression on the Macintosh in Office 2004/2008 (to the point at which I no longer used it on the Mac in 2008, it was pretty horrid) - but they returned it to (mostly) feature parity as of Office 2011.
Sharepoint, on the other hand, is complete crap on a Macintosh. It's almost like it's been designed to be bad.