BigstackD uses devil forge and seems to rate them quite highly. It's a devil forge burner I've got for when I get round to building a forge. They are meant to be very good.
We brought one of the square ones for work with the double burner. Certainly works well. The only thing that is not great is the insulation which is like a fibre matting( that can be harmful if breathed in ) then you have to rub a clay stuff on before using but we have now brought proper fire bricks to replace the matting with.
You would be much better getting a square one other than the round one, the round one is a bugger to put the paste onto, and as someone has mentioned with the square one it is easier to use firebricks, its also a bigger forge and more stable.
These are very good cheap forges, and they work very well even with one burner, obviously gettting the metal at , and holding it at a critical temperature is not easy, but a very useful tool. Easier to seal the nd of a square one too, with a firebrick.
I built my own , two tar burners and a big bottle of propane , and then to turbo charge it I removed the nozzles from another tar burner and put pure oxygen through that for those times when hot isn't hot enough .