Physical disk or VHD for Hyper-V R2

Using Hyper-V, what are the pros/cons of using the "Physical Hard Disk" option when adding a drive to a VM as opposed to just creating a fixed-size VHD that is as large as the disk?

The intention is for this disk to be allocated to a single VM so there isn't any requirement to have anything else using it.

I use VMs because they are portable. When you attach a physical disk, you lose most of the portability. It is much easier to copy a VHD file to another host than it is to move the physical disk between them.

The thing you have to think about is portability versus speed. It is largely accepted that giving a VM a real raw disk to work with is the largest performance gain you can make. When a VM runs in a file, it has an operating system thinking it's writing to a file, which in turn is asking an external operating system to write to a disk.

Disk write performance is probably the largest problem a VM can have.

More information: Coding Horror: The Single Most Important VM Performance Tip