The current generation of beam weapons are still quite bulky and primitive. Most are hydrogen fluroride (chemical) laser type that flunks the portability test, unless if you think ICBM-sized trucks count as portable. Also, because of mobile requirement and physics (energy dissapates over distance in non-vaccum environment), the effective range of "mobile" ground-based laser systems are only 2km-5km, comparred to 747-sized airborne systems like ABL (~300km).
One major advantage of laser-based systems is cost-per-kill, since the chemical fuel is much cheaper than interceptor missiles, or even CIWS ammunition (tungsten/DU). CIWS guns are more mature, but despite what the manufacturer claims in effective range up to 3km, they're still point defense systems where hard-kills occur at ~300 meters. The lack of range makes CIWS guns unsuitable for defending a wider area.
Which leaves us with... missile-based systems like the Patriot and S-300. Geez, million dollar missile vs. $20 Katsuya rocket.
