I get very good results from mixing the compressed sawdust logs with regular cordwood. Once I establish a decent coal bed, I’ll mix either 2 or 3 compressed logs (depending on how cold it is outside) running N-S, with a small gap in between each. Then I’ll put 2 splits running E-W across the top of the compressed logs. Once I get good flame going, I’ll damp down the primary air in steps over the course of maybe 30 minutes, from 100% down to 50%, then down to ~25% and then down to between 5% and 10%.
In that configuration, I can get at least 6 hours and, in most cases, a little over 7 (again, depending on how cold it is outside) before I need to reload. If I need to get a really long burn time, I’ll make a tightly packed cube of 4 Envi-blocks, with the bottom ones running E-W and the top ones running N-S. Again, you need a good established coal bed before you do this, and it’s best to rake the coals forward slightly so that there is a slight slope running towards down towards the back of the stove. In that case, I can easily get 7 and as much as 8 hours of burn time.
I will be the first to admit that good seasoned cordwood gives you more bang for the buck. However, I was willing to pay, in my specific case, a relatively small premium in order to enjoy the benefits of the compressed logs, including ease of stacking and storing, less ash, and long burn times. Now, that premium could very well increase over time, and as I develop a better storage infrastructure, I’ll probably increase the amount of cordwood I burn.
However, if you can get a decent price for the bricks, then they can be a good choice - I don’t think they’ll ever be as economical as seasoned cordwood, but you have to know why you are paying that premium.
One last thing - there is a lot of trial and error involved with the compressed bricks. I’ve been futzing around with them all winter, and I have certainly found that in different configurations, you get a lot of different results of burn times and resulting heat. I’ve found some good ways to burn them, but I’m sure that there is also room for improvement on my part.