The Joomla! Extensions Directory ™

Say you have these categories:
Food (catID 1)
Fruit (catID 2)
Vegetables (catID 3)
Bread (catID 4)

And you have these articles:
Bananas
Cherries
Carrots
Celery
Cereal
Tortillas

You organize them like this:
Bananas (Food, Fruit)
Cherries (Food, Fruit)
Carrots (Food, Vegetables)
Celery (Food, Vegetables)
Cereal (Food, Breads)
Tortillas (Food, Breads)

You make category blog menu items:
Food
Fruit
Vegetables
Bread

If you click on Food, all of the articles will appear. If you click on one the articles (or readmore):
The article appears as it should.
The parent menu item is Food.
You can navigate through the articles using Prev-Next.

If you click on Fruit, only the articles included in the Fruit category will appear (as they should). However, if you click on one of the articles (or readmore):
The article appears as it should.
The parent menu item changes from Fruit to Food.
If you navigate using Prev-Next, you will see all of the articles in Food, not the articles in Fruit.

This is because, when you click on the article, it grabs the article's catID with the lowest numeric value regardless of the category from which the article is called.

If this OK or a non-issue for you, I would recommend one of the non-commercial options. They'll do the same thing, so why pay?

In my opinion, this deficiency makes this component completely pointless. Why go to the trouble of cross-referencing your articles if the user will be taken to a completely different section of the website when they investigate an article in a category that has drawn their interest?

As far as support goes, I don't really want to get into that, but suffice it to say I am not sharing this info because the support was fabulous. The developer is aware of the issue, and I guess has chosen not to complete the component. Good enough is good enough if it keeps pulling $50 a pop, right? To his credit, the developer did offer to return my money, rather than work on the problem.

If you are wanting to create a true cross-referenced library of articles, keep looking. I am.