How's the quality of the HDCD's from China/Ebay

I bought two Coldplay cds. They sound ok but I haven't compared them with US versions. I bought a US version for my sister, I'll have to check it out to see which is better.
I will say these two cds don't present the soundfield depth that cds such as Joni Mitchell's do. I have compared "Blue" and "Court and Spark" HDCD against nonencoded versions and believe there is much better sound with HDCD encoding. I believe they were also remastered so that could contribute significantly to improved sound.

They seem fine to me however I am always hungry about an hour after playing them.

A lot of the sellers of these discs have been rumbled and have disappeared with the discs that say hdcd but no light comes on. Quality is good on genuine discs. Quality on others(bootlegs)is surprisingly good at first but ultimately tiring.