You cannot compare "overview" and "opinion". Doing so would be committing an
error of category. An "overview" describes the scope of the article subject. An "opinion" describes the claim to applicability.
For example, if I would have focused on just one aspect of Linux Audio, say, DAWs, then this would not be an overview of the platform. But the scope of the article is to look at the most important elements of the platform as a whole. Therefore, it is an overview.
If I would have spent enormous amount of time interviewing people in the Linux Audio community, gathered statistics and presented a conclusion based on a very objective, well-balanced process of evaluating data, then this overview would be more than my opinion, it would be more like research, not just opinion.
But in this case I give my perspective. I did not interview other people, I gave an overview based on my own experience. In other words, I am not claiming that this would be true for everyone. I would claim that this would be more or less true for people with the outlook and needs similar to mine.