Northland is good from what I've heard. It's most likely people just saying it's good because we lived in the town it was made in. Just a conventional oil. Pretty small plant. My old roommate used to use the stuff. I got him to switch to AMSOIL and he hasn't looked back.
The marketing behind Northland must be horrible. Even in the same city that the place is based it was hard to find the stuff.
I lived in Cedar Falls/Waterloo for 5 years and still go there once a week (fiancee lives there). Northland is a pretty small company. While they do sell some "virgin" oil most of their basestocks are recycled/re-refined oils. The only place I've ever seen it carried in-store was at an Advance Autoparts store in Waterloo.
Several of the car dealerships (including the two largest) in the W'loo/CF are also using the re-refined Northland oil for their quick-lube services as evidenced by the Northland banners displayed in the shops.
From what I know, the oil isn't bad but it isn't great either. Regardless, the business's bread and butter is not engine oil, but instead automotive parts solvent.. competing heavily with Safety-Kleen in within the central Iowa market.
I've long argued that ST isn't an inferior oil, nor can you argue that it's better based solely on add levels. As others have pointed out, base oils figure in here too, although with the variabilities in testing labs and differences in cars it's a bit hard to prove anything.