LEDs will draw less power but the amount of "lumens" - brightness intensity, will be less with LEDs
so pros for HIDs:
-big range spectrum of lighting colors (3k to 14k)
-a lot brighter than stock headlights
-about the same hours as halogens
cons:
-runs hotter than halogens
-more parts/more prone to failure
-sometimes the power draw can blow a fuse since it draws more power
-draws more power
-if you arent using projectors, you will have HID "flares"
-there is a cool-down time and a start up "warm up" time
LEDs:
pros:
instant off/on
a little more brightness than stock halogens
has a ton more hours of on time than HID or halogen
cons:
runs cool
draws little power
limited color spectrum (from what i know so far)
not as bright
can still cause the "Flares" if you aren't using projectors
If it were me, I'd go with the LEDs
My next subie will have em in the car (currently have HIDs in all my cars and they've been just fine - had one HID blow out after 6 years but thats about it!)