Diana rework feeling like a failure.
New Diana is having a Placebo effect on people. While mathmatically her damage is up only when she has R up and pulls more than 1 person, she does less damage over all now. Her Cool downs before were short with 15 seconds being the highest Cool down at lv 18. You could consistently get high damage off for surviving but now you put all your eggs into one basket with having a R that has most of your damage now.
Diana lost her identity now since she is not tanky enough to be a Fighter/Diver and does not do high damage consistently anymore because of her R being changed. The rework fixed none of her issues with having no escape or being feast or famine. Her ratios being lower only make it harder to go tankier because you lose your damage and your damage is tied to your tankiness [W]. Your passive got cut in half in exchange for more Attack Speed but you dont live long enough to do it. All this rework did was turn Diana into a scuffed Irelia. The trade off from getting to 6 was that you got short Cool downs and high damage. The reason to pick Diana was because your burst was reliable unlike other assassins who needed to hit things to kill. If you were strong enough you could just RQW and someone is dead. You probably died too but its the same thing now except you cant do it every 15 seconds and it can be dodged which destroyed her identity.
There are already other post explaining why this rework doesnt work but I am adding my 2 cent in.