NTSC works perfectly, tested with Disc and USB. The key is to force the loader settings to "English". Google for 'galaxy green screen' if you have problems.
It DOES work! And the saves are compatible!
It's just not fixed in the firmwares. You have to use a cheat code (as before with the US Version, before all firmwares were updated). I just found it out myself while playing around with R4CCE. Code is the same, only other game id!
Game ID: YGXP...