As I think it through, it may be more of a better "power rating" as well.Here's a last year's comparison from WKC.
Leftover Dry Ash Content Breakdown (bucket weight subtracted out):
Kingsford Comp: 5.9 oz
Trader Joes: 9.4 oz
Stubbs: 10.1 oz
Kingsford Blue Bag: 10.7 oz
The Kingsford Comp was the clear winner in this regard coming in at almost half that of the competitors. Once again the TJ’s Stubbs, And KBB came out very close on paper.
http://weberkettleclub.com/blog/2015/08/09/charcoal-showdown/
I have no idea why the results are so different from different testers and users.
If I find the time I'll do one myself soon.
I will have more unburned briqs in my baskets after a cook with Stubbs as compared to KBB.
Stubbs is of higher quality, you just have to decide if it's worth the extra cost.