As an MBA (and hacker), I can say that I would absolutely prefer a PDF to a word document. If you really want to make comments, just made a comment in the PDF. Adobe Reader, though I prefer not to use it, lets you easily make comments, and this is the program most people will be using.
I think the m-team types understand "Track Changes" better than they understand comments in PDFs, but if your team prefers PDF, more power to them. I'd obviously rather generate a PDF than a Word Doc, and I'd rather generate a wiki page than a PDF, and an email than a wiki page. But life's pretty short.
PDFs are a really valuable tool when you don't want people to modify your document, and you have the political capital to refuse changes.