So, from what I've seen, sword charges are by far more useful than gun charges, which are rarely used outside of the blitz needle. More to the point, sword charges are MUCH too easy to spam at monsters that are otherwise dangerous; gremlin thwackers are frightening, but not if you've got an acheron throw them across the stage. If players were forced to give up the "charge and run" technique, or at least have it nerfed, swords would be harder to use.
Also, gun and bomb charges are inconvenient to carry around since they reduce movement speed; it's annoying to charge a gun and go to the next fight with that charge. So, here's what I think should happen;
Make sword charges have the same movement speed loss as guns, while charging. ALSO, make all movement speed losses while charging not take effect once a weapon is fully charged.
This makes it still possible to "charge and run" but players must back off to a safe distance before initiating a charge; a monster will catch them if they resume charging immediately. It also gives gunners and bombers the ability to carry charges from one fight to the next without moving slowly and getting left behind.
the movement speed is there to balance out the weapon power and effect. if the movement speed was gone after u charged, then the counterbalance for each individual weapon would cease and that would over power the weapons.
so, weapons like electron charge or gravity bomb would be greatly overpowered. i don't think this is a good idea.