The AER9 was actually not the top laser rifle in service at the time of the Great War. The model line went up to the state-of-the-art AER12, which saw service in a handful of specialty units. The reason that the AER9 is much more commonly found is that it was much sturdier and more reliable than the models that followed.
The AER9 features a titanium housed crystal array which proved to withstand long years of exposure to the elements much better than the gold alloy housing of the later models. As a result, the crystal arrays stayed focused within operating parameters, rather than falling completely out of focus like the newer models. Power is drawn from microfusion cells and processed through a wave/particle diverter manufactured by General Atomics International. The diverters are protected by a carbon-fiber housing, preventing frequent malfunction, but when a diverter fails the weapon becomes unusable.
As with all energy weapons, the AER9 can suffer from poor performance if not properly maintained. The crystal arrays and non-mechanical components are delicate and if not properly serviced can lead to a loss of beam intensity, overheating, and energy regulation failure.
With over 3000 DPS and 1000 damage per shot, this laser weapon will destroy anything in your way. If that's not enough, this weapon always gives critical hits for an extra 22 damage, a negligible addition to the already massive damage but also ensuring that your target will be reduced to a pile of ash.