https://northidahoenergylogs.com/ I got some of these, here's what I found. They take a bit to get going, then burn incredibly hot. If they split apart or if I put more than 1 log, it's almost like a runaway and I don't like that. I've tried different orientations but find that on a cold start or a reload, I put some splits first, then put the log E-W at the back, then one in front of that and one over the top in the gap. They kinda expand as they burn, so this helps keep the chunks together when they come apart. Not sure if bio bricks do that, but these do. I get 5-6 hours of useful heat from that, I measure it as when the fan turns on to when it turns off, and still have coals. Overall, I really like them and will get more later this summer.