Long burn time on those leaky pieces of crap is impossible for me. I have one out in the shop and fill it full. Mine will run pretty hot flue temps so I have to watch that.
My brother has one and I had one for a bit, he loads it with as much as will fit even sits a small piece on the door frame. He can get it to last all night. Me on the other hand couldn't get line burns so I bought an OWB!!!! Best money ever