So much to my (short-lived) glee I finally got my green steel weapon up to tier three this evening. I went Positive+Positive+Positive hoping that my weapon would become a disruptor at the end as was said in the spreadsheet on crafting.
When I hear something called 'Greater' I usually assume it's better than the regular version. In the case of Greater Disruption, this is a false statement. Greater disruption procs perhaps 1-3% of the time against undead only and hits them with disruption. (They get no save from what I can tell). But here's the thing: 1-3% isn't as good as a regular disruption weapon! Your target will fail it's save on a 1 every time. And a one is rolled not 3, not 4 but 5% of the time on a d20! This means that you are less likely to disrupt an undead creature with a greater disruption weapon than with a standard disruptor.
Not only is that frustratingly underpowered compared to a regular disruptor. It's also frustratingly underpowered compared to the other tier 3 single element upgrades. All of which proc the same amount of the time, but are effective against all targets, of all power levels and all types. I would rather be doing 300 or so extra damage 1% of the time against all targets rather than have an ability that I already have a better version of on a weapon that I haven't been farming to get since Mod6 came out.
So it would be nice if you either made Greater Disruption worth getting, or if you named it 'Disruption blast' so people like me wouldn't be fooled into crafting a clearly inferior item.