- Lower system requirements to deploy Ghost images than WIM images
It takes effort to move an existing set of images to a new format, and work out a way of deploying them. Unfortunately WIM isn't a drop-in replacement for Ghost (see next point).
Lower system requirements
I can build a 2.88Mb floppy disk image using Bart's modular network disk system that will include support for all the network drivers I need, and have room for the Ghost executable. I can customize the floppy image to deliver a single Ghost image, or give me a command line from which I can invoke Ghost and manually choose. These 2.88Mb floppy images can be easily delivered to PCs via PXE. To deploy a WIM image I need imagex.exe, which will only work under Windows (XP, Vista or WinPE). The resulting ISO or WIM image I need to deliver via PXE is 10 to 20 times larger (at a minimum), takes a lot more building and possibly won't run on the lower-end hardware I still have to support.
The best part about WIM is that a WIM image isn't frozen. I can mount a WIM on a folder and treat it, for the most part, like a standard directory tree. If there's a typo in an INI or INF file, I can correct it. If I need to change a driver file, I can. I don't have to go through a 20 minute capture process. This stood me in really good stead during a recent server build project...