I never understood the reasoning behind the negative effects on L5, 6, and 9 devices. In fact I don't recall there ever being a given reason as to why they have negative effects there seems to be no rhyme or reason too it. There are also some weapons, engines, shields, and reactors that have negative effects as well for no apparent reason though the devices seem to have by far gotten the worse of the random negative effects. And yes there are a few L9 devices that don't have negative effects but they are almost exclusively loot only, unique, non manu. Who wants to spend 8 skill points plus huge sums of money upgrading to level 9 devices when they are only slightly better in terms of buffs to level 8's, have significant negative attributes, and are much harder to get to 200% quality then the level 8's? Only way this PS is upgrading to L9 is if I get a few good unique L9 devices.