Today The Telegraph has a post about a study showing the MacBook Pro is the best computer for running Windows. I've heard this before and don't doubt it for a moment. Apple makes the best computers in terms of quality. They are certainly not the cheapest, but they are the best.
They are also the best for cross-platform development with Real Studio. Because you can run OS X, Windows and Linux all on one computer, what more could you ask for when it comes to convenience? At Real Software, most of us used to have at least two computers: one running OS X and the other running Windows and Linux. When Apple made the jump from PowerPC to x86, we got rid of half of our computers!
If you're developing a cross-platform solution with Real Studio that is going to include an OS X version, you'll need a Mac anyway, so why not just make it your primary computer even if your primary OS is Windows or Linux?
Here are two options for running Windows and Linux (and OS X) from a Mac:
1) Apple's Bootcamp: It's free and you can boot into Windows so you're getting the full power of the Mac running Windows, rather than sharing the processor with OS X. The downside is that you can't run both at the same time and setting it up to run Linux could prove challenging.
2) VM Ware/Parallels: Both of these software applications will allow you to run multiple OSs while running OS X. I use VM Ware and have Windows XP, Windows 7 and Ubuntu Linux available to me in addition to OS X. The downside is that when you are running one of these, you are also running OS X, so Windows or Linux can't use the full power of the computer. However, I have found that not to be much of an issue with newer Macs, as they have plenty of power. Just make sure your Mac has lots of RAM, as that's often the difference between the performance being great versus not so good.
Update: Microsoft provides most versions of Windows for testing for free download. They available in Parallels, VMWare, and VirtualBox formats.
Macs are more expensive than the average Windows PC. There's no doubt about that. But if you need a Mac, it might cost less to buy a nice one and use it as your only computer with the convenience of running OS X, Windows and Linux all from one machine.