Difference from custom content type + views?

Honestly, the only reason this module came into life is because the menu item wouldn't stay hidden unless it was created by a module. With a manually created content type (and, BTW, Views is not needed at all), and a manually created menu entry, when you are not logged on the menu item gets "promoted" to the primary links, making it accessible to anonymous users. Not exactly what I wanted.

The weighting and stickiness is there in the -dev version. It's stable, so give it a try.

Are there ways this could have been doen without a separate module? Absolutely. But the site I originally did this for had neith an access control module nor Views. I know, some would have you believe that's not possible. But there are many simpler Drupal sites out there that simply do not need either. Hence, a solution like this is needed for some people. By the way if you look at the sizes of those modules, you'll see that Sitenotes is smaller than even TAC_Lite, not to mention the gargantuan size of Views. I've seen Views exports that are larger than Sitenotes just by themselves. So I would expect Sitenotes to be much faster and require much fewer resouces. But, in the end, it's always up to the site's designer.

So is it possible to create a "summary" page for a content type without using Views?

Yes, it is, and it's not hard. I don't know why this function was left out of D5 when they moved basic CCK into core. I would have thought they would have mirrored "taxonomy/term/xxx" with something like "node/type/xxx," but they didn't. http://drupal.org/project/get_content_type.