I bought a random one at the thrift store a few months ago, it's some no name brand. My only requirement was finding one that didn't have any scratches on the Teflon nonstick coating on the pan.
It has been amazing, it takes literally 5mins to measure and throw the ingredients in there and push start. Took a little while to fine tune the recipe. It's nothing like baking bread but I completely stopped buying bread after getting the machine. Now I can still bake when ever i want, but its an easy way to make sure I always have bread around.
I read on r/BreadMachines that the brand really doesn't matter, just buy one for 20usd or less and get started. So far it seems to be true for me.
I would agree. Biochar and charcoal are fundamentally different, and it's unfortunate that the two get conflated. Biochar is produced at higher temperatures then charcoal and doesn't add to atmospheric carbon dioxide levels during production (if produced correctly). On the other hand charcoal is produced at lower temperatures and is not clean to produce so does add to atmospheric carbon dioxide levels.
this seems like a pretty good general overview: https://rosysoil.com/blogs/news/biochar-vs-charcoal