I got stuck with a fake 'new'; it was a dirty re-soldered board refurbish with a SSD days from failing, it dropped into read only mode and wouldn't let me reflash.
Years ago you could spot the fake new ones easily as the box had a row of keys instead of a spacebar for the raised image of the N900.
I recall another real fake N900 which had a DVB-T circuit and maybe even let you run J2ME games and apps but looked like a N900.