They are all initially suppose to be the same. quality depends simply on whether its fake or not; it either is or isnt 100% GH compound. personally, IMO i would prefer GH made in the USA simply because its more trusting than foreign products,although there are tons of great products out there it is a bit on the risky end of things. Unless you know someone its near impossible to know who to trust with this stuff.
If it came down to choices:
1. soma
2 or 3: gena / jin either or