No one wants to touch this? I found the following:

XP ECM40UT3 is the newer version
UMEC UPO653S-01 is the older version

But this is old info. Any updates?

DSP6000, DSP5200, DSP5500VC, P300W, SW1600, G68, 568.2, HD621, G57, G55, Oppo BDP-105.