Not an expert, but the easiest way to differentiate betwen the two at this moment is by identifying the shape of the regulator needle wedged between the swan-neck wire end and the fine adjustment screw.
The Chinese ETA 6497 with CDG and working S/N regulator has needle that looks like a 'spike', while the real Swiss ETA 6497 with CDG and with working S/N regulator comes with the needle reminiscent of a 'dagger'.
Eddie Lee's latest 111H with Asian mov't shows the chinese movt:
http://www.replicacollector.com/members ... opic=25524
Swiss ETA 6497 is shown below:
http://www.paneristi.com/reference/vend ... _111_2.jpg
Other details are almost undistinguishable to the naked eye, except the wrong OFFICCINE PANERAI letter size and font (yup, still there), and slightly rougher finish of the CDG bridges - the latest Asian 6497 rep mov't is really work of art, at least from cosmetic standpoint.
However, I'd stay with swiss ETA if I were you, extra $100 you pay for one of those will guarantee you at least 25-30 years of enjoyment...on the other hand no-one can guarantee the quality and lifespan of the latest Chinese ETA copy.
Hope this helps,
babola