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.

From serverfault David Gardiner

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

  From BLAKE

• 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.

  The disk writing problem is probably the largest problem a vm can have

  You might want to read this to get more information from some random blogger guy http://www.codinghorror.com/blog/2006/10/the-single-most-important-virtual-machine-performance-tip.html

  Jake Oshins : While it's true that VM performance can be greatly increased by making sure that the VM has adequate storage bandwidth, even the guy you're siting doesn't try to say that you have to expose the disk directly to the VM. He just says that you should dedicate a disk to your VM. Putting a VHD file on that disk preserves flexibility without compromising performance much.
  From Stewart Robinson

• I doubt that you could measure any performance difference incurred by putting a VHD on that single disk. Try it and see. I suspect you'll want to preserve the flexibility that BLAKE mentioned.

  From Jake Oshins