Disk Cloning (backup/restore) can work if you have identical hardware, and aren't too concerned about using a lot of MS central management tools (SCCM, WSUS, etc.). If you are simply deploying workgroup machines, that may be the easiest way to go.
If you're working in a domain environment, you may want to consider using an imaging tool (even for a disk clone) - sysprep, shutdown, then capture the image. I'd suggest something like Clonezilla or Ghost. That said, if you don't have identical hardware, this can be more trouble than it's worth, which is where something like Windows Deployment Services and WIM capture comes in.
With WDS in 2008R2 and above, you can simply sysprep, boot to WinPE, capture an image, then load all your drivers in the WDS driver store, and as part of the deploy process, all of the appropriate drivers will be sucked down to the image. That said, it requires a lot more work to set up and configure than bare image capture, but as you mentioned, you can keep your reference image on a VM, snapshot it, and work more quickly as a general rule.
Really, it's all a matter of scale. For me, personally, anything over 5-10 machines I would go the WDS route, anything smaller, I would use a tool like clonezilla.
Best Answer
Native VHD Boot may be one option. (Should only be used in test environments, not production).
http://social.technet.microsoft.com/wiki/contents/articles/516.how-to-boot-from-a-vhd.aspx