Well, backing up the entire registry do have some negative aspects. If you decide to restore such full backup after some time (i.e. days) you might end up with a broken Windows. This could happen if something changes at drive configuration after you have created the backup, the backup still contains old data but the files in use are new ones, if you then restore the backup no one knows how the old data in the registry and the new files on hard disk work together.
Similar havoc could occur if you have taken a full backup, then install new device drivers to the system and the decide to restore the backup, the registry would then contain the data of the old drivers and the new drivers might not handle it very well.
Of course, this could also happen with the partial backup mode of Macecraft's products but the possibility of such event is rather theoretical.
My opinion is that there is no need for full registry backup. If you wish to do so, I'd rather recommend XP's Restore Point system since it doesn't only backup the registry but also the system files, and thus avoids the possible problems discussed earlier.
