Doing some statshammer with my prefered method, the guestimate on eldar heavy weapons [the origional purpose of this thread]
For the same points I can have two war walkers with a pair of scatter lasers or three with a pair of shuriken cannons.
These two have been earmarked simply because they fill the criteria of being cheap units and throwing down a hail of shots. Principle opponants to these will be nids and orks, with other choices prefered against other enemies
Basically the scatter laser twosome get 16 shots at s6 ap6 36 inch range. The Shuriken cannon ones get 18 shots, s5 ap5, 24 inch range. Identical costs.
Vs Orks, they do about the same. Against the cheapest nids, the shuriken cannon is a better option.
Benifits for Scatts, is that I could add a third and increase the units overall firepower even more. This is logical, although it goes from 120 to 180 points and is expensive.
Chief benifit for equipping shuriken cannons is individual units are very cheap only 40 points. It is 50% more for the scatts. So I get more survivability for my points too, by having extra models.