I have a 1983 GS1100E and the front rotors were warped. Really harsh jarring when front brake applied. Suzuki rotors pricing and EBC not in my budget. Spoke to the ebay seller in China about his rotors as well as researching various forums. Both inspired confidence. I purchased 2 rotors for $130 shipped to my residence. I no longer have any shimmy when front braking. Smooth stops that draw my bike down quickly.
Im satisfied with the parts. Many do not like "Made in china" but let me tell you money is NOT plentiful in my household.
For the record- I am not an aggressive corner carving hard rider. I dont know how the rotors would hold up with hard braking and excessive heat build up.
The seller only had Left side rotors. I bought 2. The orientation of the cooling cross drilled holes are backward on one side. Not very noticable.
If I were a weekend racer putting my bike thru hard braking I probably would have found a way to buy OEM or EBC.
I didn't find the right solution from the internet.