So I fire up VirtualBox and go to create a virtual machine via its GUI and... err... it doesn't allow me to assign physical drives to my VM. Which is one of those "WTF?!" moments, because the underlying QEMU that VirtualBox is based upon certainly has the *capability* to add physical drives into a virtual machine, but a bit of Googling around finds that you must do some cryptic command line hacking to make VirtualBox do it. The GUI won't do it.
At that point, realizing that VMware was point and click and ridiculously easy to set up and did what I wanted it to do without said hacking, I said "F*** that" and uninstalled VirtualBox. It may be that VirtualBox could perform better than VMware Player. But my time is more valuable than any tiny increment of performance that VirtualBox could potentially give me compared to VMware Player.
Next up: I check out Windows Virtual PC and see what I can do with it. For one thing, it'll be cool to try Windows XP Mode, even if it turns out not to be useful for virtualizing Linux...