When it comes to your personal life, it's probably very limited. That's because most personal decisions involve preferences, and it's completely normal for you to be subjective when making such decisions. The point of ACH is to help you think objectively about objective facts, not keep you from thinking subjectively about things that are inherently subjective.
Argument-mapping software would be particularly useful for controversial topics where it's hard to judge just based on the appearance.
For example, take cryonics. An 'outside view' would be that it's largely scorned, associated with nutcases, etc.; but its partisans make an 'inside view' of specific technical arguments and say the facts overcome the outside view.
A mapped out inside view would be easier to follow for non-technical folks, and at least make clear what technical points are disputed. (eg. if the cryobiologists' counter-arguments are basically 'yes, it's possible except for one small issue with synaptical vesicles', an outsider might think that's soluble issue and decide to believe in the whole thing)
Of course, so far I know of no one who has put together a useful argument map like this (and all applications seem to be in niches - like the CIA), which sort of suggests that perhaps it's not a good tool at all or is too heavy-weight or something.
