Laser Weapons

In a physics class I was in we worked out that the amount of
energy required to make a clean hole through a tank was about
the same amount of energy required to make a hole through a
person.

An insignificant amount of reflective armor makes your laser
worthless, as does clothing of the same color.

Let's say you have your uber laser.  It pokes a hole through
me.  Now I have a 2mm cauterized hole.	There is a pretty
good chance I am still functional.

Or, alternatively, I have a 2mm hole 3 or 4mm deep and a cloud
of steam in front of it blocking the beam.  I'd also have a
nasty burn.

I hope you don't have to go into combat on a foggy day.  I
also hope your opponent with his old fashioned tech and 
smoke/aerosol anti-laser fog.

I can buy a laser as an anti-tank weapon.  I really have to
suspend disbelief in the anti-creature category.  The massive
energy required is much better used throwing small pieces of
mass at your opponent or prey.