This is an inaccurate comparison to VMWare Fusion. There are many features, e.g. Bootcamp partition virtualization, that virtualbox either forgot to mention or purposely excluded.
VirtualBox can actually do physical-partition virtualization, but you have to produce a VMDK file that points to the partition you want, and use that as the virtual disk. (Oh, and run VBox as root.) Conveniently, I've written some code to produce such a file: https://github.com/vasi/vmdk-raw-parts . Enjoy!
Aha, cloned! Thanks for this. I had to make my VMWare vmdk for my GPT partition by hand :-). I've been dreading the day when my disk changes and I have to recreate it. Now I will not.
Yup, it's using the physical partition, so all changes are preserved. Whether you want that or not.
I suppose you could use a snapshot VMDK to put the FS changes into a file, which you could then keep or discard. No idea if VBox or even VMWare actually supports this behaviour. Nor can I think of any particularly good use for it!
You can set up VirtualBox to use a physical (ie. Bootcamp) partition or disk. It's not as easy as in Parallels, but it isn't difficult and is explained well in the manual.
In the case of a free product like VirtualBox where you're not paying for tech support, there isn't a difference.
Unless you mean that there is a difference between what merely happens to work and what the developers strive to ensure works. In this case, VirtualBox definitely "supports" using physical disks and partitions (though they describe it as an "advanced" feature).
Because most things you would want to do with parallel port that actually work through all the layers of virtualization and emulation (ie. connecting a printer) can be done equally well with emulated serial port.