If you buy a pre-2012 SRAM Red derailluer after March of 2012 you are getting ripped. The new 2012 SRAM Red derailluer with Yaw is completely awesome, with shifts so fast it will blow your mind; the old SRAM Red is terrible.
It has a cage that bends and over time your chain drops as fast as Andy Schelcks dreams. Not to mention it shifts no better that its Rival brother. Pass on this and buy the new SRAM Red Yaw.