I can't speak for Thailand, but in China that I definately know about, medical would seem to be concerns. It does have very good hospitals now and excellent equipment. But, the doctors are not yet well trained.
I'd think twice about surgery in Mainland China (and absolutely would never go to a hospital in Hong Kong).
But, in Mainland China you can get a top quality CAT SCAN and MRI (both) for about $300 (that's U.S. dollars). And on new, state of the art GE or German made equipment.
You would think that HK doctors (British trained?) would be better than their mainland Chinese counterparts...
There is no way that I would go to a hospital in either, lest my kidneys make it back to the states before me.
If you speak Chinese, Prices can be 1/10 of that at the local hospitals. However, the foreign medical centers in Shanghai are very good. I've had outpaitient surgery at a foreign medical center only because insurance covered it. If I did not have insurance I could have had the same procedure done by the same doctor, for 20% of the cost.