The sulfur coated urea I get also has 5% sulfur and 2 or 3% iron. It seems I am getting pretty good color and not alot of surge growth, but I might try and locate some of the other. In most of our clay over limestone soil, test were showing that the P and K were buiding up so I swiched to N only except for fall. I may need to get some tested again since it has been awhile. I might also try and find some of the other sulfate type nitrogen.
To the OP
I did not mean to hijack. I was just wondering about what was already posted about the urea.