Pete,After reading your comments last night, I ran both lights simultaneously on the highest settings with the same brand of fresh batteries (purchased at the same time) in each in a very darkened bedroom with no other light placed approximately seven feet from each other. After one hour I did not really notice any appreciable difference between the two. After two hours the Siege, to my eyes, appeared just negligibly brighter. After three hours, the UST was going strong while the Siege had a slight but noticeable drop in brightness. I didn't persist since sleep was calling after about three hours. If I had carried on the test overnight, I would conclude that the UST would probably just edge the Siege in overall brightness. Both globes were still cool to the touch after the three hours. I'll have to try this sometime.
I think both are excellent lanterns that can be used for walks around the property at night, taking the dogs out, camping, lighting dark closets, accessory and additional lighting in rooms, etc. I think it just boils down to personal preference.
Edit: Alkaline D cells used in both lanterns (Duracell Duralock)
Thanks for taking the time, spending the money, and making the effort to give these two lanterns a run-time / brightness comparison.
From my very limited testing experience with the Ozark trail lantern, I found that the batteries do recover a little bit (that may be seen for an hour) by letting them rest for a number of hours. In other words after the lantern has been off for the day, if you were to use it again at night, the lantern will be a little brighter for the first hour, but will then continue to decline afterwards. With the Ozark, the brightness dropped most (but at a decreasing rate) for the first five hours, it then decreased at a much more gradual rate for the next ten and twenty hours. At 72 hours it was still running, but wouldn't be good for much more than a marker.