In my opinion, putting an SSC-P4 in the L4 is a cop-out.
The original L4 was much brighter than other similar sized Surefire lights and the beam pattern was the much coveted,
floody "wall of light" which offered something usefully different.
This is because it had a Lux-V (quad-die) led in it compared to the single-die luxeons around at the time.
With the so-called "improved" version, the output and beam pattern are similar to a whole host of other lights
with this generation of led in it, like the E2DL, for example.
So its only "improved" because the present generation of led emitters are much more efficient than originally,
but not because of any innovation on the part of Surefire or any desire to recreate what set the L4 apart in the first place.
Surefire should have replaced the original lux-V with one of the new generation quad-die emitters instead of an SSC-P4.
This would have again resulted in a brighter than normal wall-of-light compared to the L4's contemporaries.
I've had my original L4 modded with a Cree MC-E by darkzero and love its utility (it has a McE2S in the tailcap to provide 2 levels).