I bought a two-burner back in 2007 on eBay. Worked really well, got very, very hot consistently. The problem was that it warped the sheet steel it was made out of. It didn't ruin the forge or anything, but it was definitely warped away from the firebrick lining. In addition, the hoses provided are rubber...not that big of a deal but something I noticed about the Diamondback's are that all the hoses are copper tubing, which I would much prefer (less chance of crimp, less chance of something hot melting the rubber and causing a problem).
That being said, I think Majestic's are pretty darn good for the price, and it appears that the manufacturer is using compressed ceramic blankets in lots of his newer models, in lieu of the delicately-brittle firebricks.
Just my two cents.
