Hi
Only problem of using a disk for mksysb image is that in case of a system crash, how are you going to use that disk based image to restore your system? Only way is to use a NIM server and boot your damaged system from this NIM server restoring the image.
NIM comes free with AIX and just need to be configured. IN AIX 4.3.3 is just a little more difficult than with newest version of AIX 5L, but it can be done.
What i have done is to burn the image taken to a DVD RAM and use this one to clone or restore another servers.
Hope this helps