How much use do you get out of your power weapons' special trait? While I've certainly not played copious amounts of table top 40k, I've played considerably more of it than I am likely to ever get to play this, sadly, and in that, "power weapons" were simply melee weapons with excessive Armor Penetration scores. Before this addition, I think they were AP 2, and now they are AP 3, so they were good for cutting down Space Marines, for the most part. Other than that, though, they don't really do anything.

Then we get to here, and Power Fields can cleave opposing weapons in half, much of the time, if you can parry (sounds right in my head, anyway), which is certainly NOT a thing in the table top game. While I'm sure they are still doing better than average damage, and have the appropriate Penetration, this quality is part of what sets them apart. In a game filled with guns, however, and with numerous creatures that don't use weapons (and that you can't "disarm" for some reason), does it come up much? Are you bisecting any weapons where it really made a significant difference? How often does it work for you? I'm mostly just asking because it seems an interesting addition, but it also seems it could be annoying, having to change things, now that a weapon got broken, and on.

So, how much of a difference do you feel it makes? Are they still just better for the Energy damage, the extra damage, and the higher Pen, or do you feel that the "lightsaber special" pulls its own weight, too?

The disintegration is important because otherwise a Chainsword is just better - that extra die of tearing gets so important for confirming righteous fury. I usually change the rule to if a Power weapon is used to parry or is parried triggers a disintegration chance.

Also it always comes down to Melee combat. If it isn't coming down to Melee combat you're not 40King properly

I like it because it's a neat, unique bonus ability that clearly sets power weapons apart from other melee arms, rather than just going the ole' "+1 sword" way. The same is true for chain weapons. In the tabletop, such details don't matter much and can (or must!) easily be abstracted as you have units fighting units, but when it gets as personal as in an RPG, you'd want the differences between characters and their gear to be accentuated.

And coincidentally, it was actually Games Workshop who introduced this idea with their Inquisitor game:

Power Weapon

A neat little spark of consistency in a sea of contradictions and differences.

In tabletop minis 40k it doesn't matter if you cleave someone's sword in twain because it's probably assumed they have a backup with similar stats. There's only so much you can do with 1d6.