64-bit guest on Windows2003 32-bit

[vuser1]

I know the question is stupid )

In VBox Manual, 1.6, we read:

Since supporting 64 bits on 32-bit hosts incurs additional overhead, VirtualBox only enables this
support upon explicit request. On 64-bit hosts, 64-bit guest support is always enabled, so you can simply install
a 64-bit operating system in the guest.

In VBox 3.0.4 on Windows2003 32bit Enterprise, the option for 64-bit Linux guest is enabled out of the box. My hardware is AMD64, but the host OS is 32bit. Does it mean I do not need "special request" and can use 64bit guest without perofrmance degradation?

[mastersrp]

You simply enable virtualization in the BIOS, and install the x64 guest OS. It's that simple, i did it with Windows 7, Ubuntu, Arch Linux and it just works.
edit:
The only performance degrade i see, is using a virtual machine :] It's always faster when it's actually running ON your hardware then on a virtual machine. But other than that, there's no performance degrade. Not for me anyway :p

[vuser1]

The specific question is: "Does 64bit guest works on host <32bit Windows, 64bit CPU> without performance degradation?"