Based on the blog description, and assuming the Swedeistanis aren't just mistranslating their own advertising.

>Unlimited "idle" lifespan. All other sentries have a lifespan somewhere between 2-3 minutes where they deactivate even with ammo remaining, even the Tesla Tower.
>In exchange, the Laser Sentry has zero safeguards against overheating. If it keeps firing, and gets no chance to cooldown, it will just kill itself.

The interpretation I get from this is that the Laser Sentry is intended to be a true additional fire support sentry. It needs you alongside it, shooting the shit it's beaming to keep it from blowing itself up. It can't be left alone or expected to pick up the slack all by itself. But if properly used, it's an effective "permanent" DPS ramp within its own radius, and not a simple burst of damage like with e.g. the MG or Gatling Sentries.

Of course, the major problem here is that laser beam weaponry is only S-tier against bots. The Laser Cannon is AP4, so at the very least the Laser Sentry should also be AP4 at minimum, sensibly it'd be AP5 since it's bigger than the Laser Cannon. They're decent against Squids too, but not as effective thanks to the Voteless. Against Bugs, they're kinda ass.