Hunh, I saw that module but the "This module doesn't have a UI" part made me assume it probably wasn't widely used
I guess for your needs, it was needing to programmatically check for the argument that led to needing this solution?
I think there are basically two paradigms to related content -- it's either specific to that exact product (which is usually more appropriate for the CCK solution, since it's just putting fields from the node that you enter as usual into tabs), or generic across many products (better for the QuickTabs-style approach).
You can also get to the former using the latter by using arguments. For example, display a one-item view in a tab that takes in the product or some other field as the argument and uses that to pull up the relevant screenshots or category-specific FAQ or something. Or you could plunk in the views from uc_views. QuickTabs is also a very popular and well-supported module.
I'm asking this for the purposes of theming (of course ) -- if we were to include tab styling in a theme, what approach should it be for, what solution gives the most flexibility?