Both these weapons are what I like to use, and both of these weapon types(save for the Illisi force sword) suffer the same problems.
The special weapon attacks for both types of weapons force you to stop and channel that attack.
Not a problem when facing a priority target. But IS a problem if youre not facing just one priority unit. Lack of movement means you take unnecessary damage if you try to get the full dps out of your special attack. On lower difficulties you just get away with it, but in the mixed hordes that often come on higher diffs, the special attacks drop steeply in appeal.
For improvement, I recommend an explosive attack, or a wider force cut for the normal 1 handed force swords special attacks. Activating the special attack doesn’t need to be changed, but the actual special attack shouldn’t take a few seconds and should just be instant, instead of the channeling we have right now when attackign something with it.
For chainsaw weapons, I recommend to make it chainsaw faster, and make it so anything that wanders into the blade(while you are chainsawing someone with the special attack) get cut as well. This will improve its usability as you are not stuck with an enemy for long, with the addition that you do not feel strange when someone clips past the blade when you are special attacking something.