It occurred to me that a typical Apple user might ask me this question after looking at the Apple Support Communities.

I would say a qualified yes. Why qualified? There are several reasons why it may not be worthwhile and several that are. Here are the pros/cons as I see it.

Pros

1. Dedicated very intelligent Apple consultants, independents or just fans of Apple work for free.
2. Turn around for an answer can be instant.
3. You get answers that might have more experience than a typical Apple store employee. Not every employee is passionate enough to work for free or listen to the experience of others and try to use non-Apple products as well to solve issues.
4. Excellent option for out of legal required support, legacy support (things Apple can’t make money off of), or third-party software.

Cons

1. Difficult for a beginner to tell whose advice should be followed. Ratings help, but even professionals make mistakes. No recourse or liability if something goes wrong.
2. Many, many questions stay unanswered. Way more people asking for help, than people qualified to help have time for.  Posters can help themselves by being brief, being specific, and avoiding jargon/cute slang. Many helpers are international, and the use of jargon is another obstacle they have to overcome to help you.
3. You might get several contradictory answers, especially when asking for software recommendations. Too many choices causes most people to feel overwhelmed and give up. Difficult to separate what is good for the posters interest, and what is the best course for the interests of the helper.
4. I think the ASC work best for those who are out of their legally mandated hardware support. Generally legacy questions can become increasingly difficult to answer as time passes. For example, for someone with extension conflicts and using Conflict Catcher, can you name the most common extension that used to cause problems for designers? I have to think about this and the older questions are the more likely our mind will play tricks on us. Reviews of third-party software are a mixed bag, because software changes so quickly and dramatically. One version can turn good software bad, or bad software good. In addition, there are often hidden motivations for the posters, so you have to keep those in mind as well.

Bottom line

If money is an issue, then posting at the ASC is a good first step. If you are looking for out of legal support for a relatively new purchase, also a good choice. If you are looking for reviews of third-party products, less useful. Least useful for legacy support. Too often even those using and fixing legacy support issues can’t do it long-term. So while it may work for a couple of years longer than it otherwise might, due to a community, eventually it will just stop working. To me, keeping current with applications and data storage seems a reasonable investment of time and money.