None of the X1900 cards come with any clock speeds higher then stock reference as of yet, none of them have a non reference cooler either.
The only real differences will be:
The box
The bundle (apps and games)
The sticker on the heatsink
The PRICE
So get whichever is cheapest, which is usually the Sapphire ones.
The only real differences will be:
The box
The bundle (apps and games)
The sticker on the heatsink
The PRICE
So get whichever is cheapest, which is usually the Sapphire ones.