I"m a big led fan, and have a good number of led flashlights and use leds exclusively on my bike headlights (both for commuting and for trail riding). That said, I feel I know their drawbacks quite well.
In wet, foggy, snowy or other inclement weather, my forward led lighting ('white') is, for the most part, highly ineffective- especially on paved surfaces. It basically seems to dissappear. In foggy or snowy weather, the backscatter is very notable. Heat dissapation is easy to achieve in a moving vehical with any type of heatsinking on the leds, so that I'm not so worried about. Just to abiliy of leds to light the road when tis needed most.
True, there are 'warm tint' leds available, albeit in small quantities (for the most part); they still suffer from a very narrow range of light emission though.
