Quality is not a factor right now,
In this context the word quality means nothing. It is a misuse of the word and refers to intangible concept that is entirely subjective and relative to (in this case) @southernguy's perspective.
Quality is ones ability to consistently build or create something to meet a specific standard. A Toyota Corolla is a high quality vehicle, nearly every car was produced to meet the exact standards that it was sold as. It was said to be reliable, nearly every car was reliable, it seats were lame grey, every seat was the exact color of lame grey and so on. But is was no Lexus. Lexus is a luxury vehicle so instead of lame grey fabric seats it's specification calls for fancy black leather. The fact that the Toyota has fabric seats instead Leather does not reduce the "Quality" of the Toyota. It simply means that Toyota is lower grade than Lexus. Quality is reduced when the black leather seats specified are delivered by a dark grey-ish leather that is spotty.
What constitutes good quality content? It is actually impossible to know as it relative to the searchers query and intent. You can take your most popular keyword, check the SERPs for that keyword and look at what you competitors produced and then try and repeat that. This is now your standard and your ability to meet that standard will determine you level of quality.
The only problem is that your view of SERPs is singular and thus biased. You may well produce a "high quality" website that meets that standard, but really what you are doing is producing content of a specfic "grade" that grade made be more or less popular. So you may be lucky and increase traffic as there are more people searching for that grade of content or you could be unlucky and achieving the highest ranking for fewer searches.
But the bottom line is that you can't produce one vehicle that is both a Toyota and Lexus at the same time. One can't produce content that is point form list style, and in depth, well researched, well explained, well sourced. Choose one, or the other. Or one can choose both, like Toyota with the Toyota/Lexus brands but then these are distinct products (distinct pages or websites). One needs to chose the one that will generate the most profit. To determine this, one needs to do research outside of simply relying on bogus "keyword tools" and test to see which approach is best for one's specific niche.
The worst possible strategy is to try and continuously adjust your content to meet the flavor of the month.
@Cralamarre, you seem to be fortunate to have found the optimal positioning within your niche. Keep it up and simply ignore the noise.