EDIT: Just to be clear I'm not trying to troll or be difficult. It's a grid with some cells that does some math. I just figured _anything_ would work.
You typically have to start worrying about using specifically MS products when compatibility becomes an issue. This is usually more true for Word than Excel, though, by a long shot (I have deep, painful experience with this)
I'm on kubuntu, I could run it in a VM though it's much simpler to open google docs in a new chrome tab and more than enough for my needs, so why bother? It's not the right tool for the job if google docs gets the job done for me with much less hassle.
I'm not an MBA number-cruncher type, but all the product managers at my (otherwise Mac-heavy) company insist on running Excel through a VM or a Boot Camp installation because the Mac version of Excel doesn't offer a lot of the functionality that they rely on in the Windows version.
There's more than enough hassles involved with running a company - doing compatibility work for office software shouldn't be one of them - just use what is the industry standard.
Also, if I have to worry about this kind of thing, it means I'm working with people who voluntarily use NT. Nothing good can come from that. ;)
I recognize that most startups aren't going for the full MS package (esp. Sharepoint), but I look at these tools as a suite that grows in power as you need it. With the Ribbon, you get great discoverability of these advanced functions as your needs arise.