I use their Office software on my Mac. It often blows. Their tech support sucks too. They're hard to reach. They're expensive. Their program is a cluster fark. For more reasons than I care to enumerate here.
It's brutal. They're brutal. How the F you Windows Weenies deal with their considerable mammoth software company bull**** is beyond me. I deal with Apple on issues from time to time. MUCH easier. Of course those issues are few and far between compared to the Microsoft issues. And when I do contact the company the tech support is 10x better. I have an office network with six Macs here. We used to have a Windows PC. We threw in the towel. It was too much of a pain in the ass. It's sitting in the crawlspace collecting dust.
I just tossed my old Entourage (MS Office email program) database on my laptop because it was hopelessly corrupt. Couldn't rebuild it. I think it's an incompatibility with the new Mac System 10.6, which I suppose is sort of to be expected. I just started over. I have the main database on my desktop.
I generally like MS Office for the most part. But Microsoft is the absolute worst. Do they go out of their way to alienate their customers? It has gotten to the point where it's easier to do anything but call them. So I try to avoid it.