My OKJ is not one of the better built, original OKJ units. It's not the newest, thinnest, cheapest one like you see most places now, but it's still a thinner steel unit. It doesn't seal up well, it doesn't hold heat very well, it's just lacking it build quality vs the Yoders.
Don't get me wrong, mine has served me well and was a great first pit, but as with anything, the more experienced you get, you understand why some things are cheaper and why the thicker, more expensive units are better.
I have a convection plate in mine with other mods and they help out quite a bit, but the HMS in the Yoders is a nice system and it's constructed very well. Plus I need a larger pit for competing.