the cree chips have come in 2 different sorts as you know...
4 x 2.5 w LEDs (GEN1)
2 x 5 w LEDs (GEN2)
these are shown in the picture below...
having had both fitted to my car yesterday i felt that the 2 x 5 w bulbs were slightly brighter for the E92, this may vary depending on what car the bulbs are being used on.
this is a picture that Teddy took yesterday (sorry for the advertisiing but this is taken off his facebook page of my car)
this shows the two different bulbs against each other