[ShocknAwe]

Gotta check the lumen output of the bulb. Temperature output only goes so far, and yes, generally upping the Kelvins reduces output.

There are a few bulbs out there with ~5000K temps which have higher lumen outputs than stock, but just barely. So you can have a whiter bulb without sacrificing real performance if you want. I think Morimoto makes one, and perhaps Osram.