The problem with Wikis is that they are often cumbersome to write specially for someone who has never made a page before and they have to go through the whole process of learning that also.
Forums are easier to post stepped instructions with embedded images and linked videos and can be done by almost everyone here.
We have a wiki at work (IT) and no one uses it, its constantly being pushed but we all default to writing and looking up word documents in a folder structure.
In saying that, there are some great threads in this forum with a lot of helpful advise, but no one takes the time to write a how to thread to sum it all up. Auto bed level thread is a good example, excellent collaboration between a few forum members and problems were solved and the thread evolved, but it is buried in a sea of posts which are not relevant or were just questions.
As you say RetireeJay, Printrbot are constantly changing their lineup, the auto bed level thread is now almost completely irrelevant as you can download new firmware which supports it. Asking people to take time out of their day to learn to write a Wiki and spend hours writing a document which will be ignored in a couple of months doesn't seem that appealing. Yes there are things which are constant throughout the lineup, and this sort of thing needs to be in some sort of "how to", but i think what is being asked here, is a section where we can write a quick and nasty short how-to that may be buried in a couple of months but thats ok because i spent less time writing it than this post. If this is the case, i would suggest that instead of a new sub forum, maybe post tags can be implemented to tag a post with [HOWTO], this way it can be searched for explicitly in the forums search engine.