Mjolnir Cannon: Changed to a clip-based ammunition-using weapon, with a reduced flux cost to compensate. Again, a change made because the current Mjolnir just... doesn't have a good niche; you're basically always better off with a specialized weapon given their current stats. Going to burst damage with a lower sustained damage gives them a viable niche where they're not directly competing with autocannons or hellbores.
Mjolnir has a niche - "ubergun" for ships with the flux stats to use it. Admitting, the only unskilled stock ship that might be able to use it is Conquest. Low tech ships probably need skills and dissipation min-maxed to have a chance to use it long enough. Mjolnir has good range, decent accuracy, decent power and range, and EMP on top. Mjolnir does everything. Compared to other weapons, Hellbore is heavy version of Heavy Mauler (optimized for anti-armor), Mark IX is basic, efficient, but horribly inaccurate, Devastator is not a long-range weapon, HAG is... good if you cannot use Mjolnir, Gauss is a sniper weapon, and Storm Needler lacks range for its size and is about as much a flux hog as Mjolnir.
On Conquest, my ideal configuration is one side with Gauss and Maulers for anti-Paragon, and the other side with dual Mjolnirs and dual flak cannons to rip everything else and have decent PD. But, because Mjolnir is one of the rarest weapons in the game that is almost impossible to stockpile, I get to use more common and inferior alternatives like Mark IXs, Heavy Maulers, and Ion Beam; or (someone else's) Heavy Needler and Devastator. On mod ships with large hybrid or universal, if it does not have enough other mounts for kinetic spam (to enable easy shield pierce from Tachyon Lances), Mjolnir is the default choice on the mount because it is just that good. There are exceptions, like Tachyon Lances on Karkinos with lots of kinetics, or Gauss Cannon on Brilliant to compliment Heavy Mauler hardpoints. Regardless, Mjolnir puts plasma cannon to shame.
Re: HAGI do not use this much because HAG is a bit too rare to replace except maybe those who have commission with Hegemony or something. But, since Hellbore lost its fireRate, HAG is decent as a proper heavy HE weapon, but it is a bit too flux hungry for comfort except maybe for Conquest, who has better things to mount (like Mjolnir) if available. It does not help that Heavy Mauler is one of the best weapons to put in any medium mount that can take it, which means complimentary heavy mounts get either kinetic or Mjolnir. Generally, my default choice for a heavy ballistic is Mark IX for being common, reasonably efficient, and effective for any ship, and compliments Heavy Mauler well. If HAG was readily available, I could probably find something that can use it.