Cassie feels so weak, right now. Yes, I understand that party of that is acclimating to her kit changes, but that passive..... So painful. It doesn't seem right that hey passive penalizes her, no one else's does that so I can't understand the reasoning behind it.
Her new Q range is, for lack of a better term, clunky and the change to her autocast makes it much harder to land an ability that was already challenging to hit with. This was already a high skill/high reward ability, but now if you land it there's no satisfaction since you will get at best one E in before they move out if range, or just close and kill you. With the decreased range it forces her to get way closer to anyone the Cassie ever wants to be and it's no longer a good tool to trade in lane.
Her W isn't a very effective tool note, yes you can block most of the width of a land with it, but the CD is just repressive and the grounded affect sounds cool, it's pretty meh in actual gameplay. Not sure if it's a bug, it intentional, but Amumu can use bandage toss from inside it's area with no problem, which seems counter to its function. The max range only cast and interaction with terrain as well as the loss of vision removed a huge amount of utility from the ability making it useful in very specific circumstances, but otherwise not desirable at all. Grounded might be more effective if it interrupted abilities that moved a champ into it, especially if you could cast it closer to yourself, but as I'd I'd rather just have a while new ability then what it is now.
Her E feels super clunky and the damage doesn't seem to have any significant impact early game even when the target is poisoned, maybe with a full build it wouldn't feel that way, but I can't get to a full build because everyone just walks up to her and kills her with impunity.
Her R was already only moderately useful since landing the stun is very difficult against anyone that knows her kit because of the casting time, now that you nerfed the slow by a third it's even less useful, not sure why you nerfed the slow, it wasn't at all game breaking or harsh.
Lastly her passive, taking away her stacking passive and replacing it with one that penalizes you while only giving move speed is pretty atrocious, especially because now the only late game spike you get out of it is a very slight advantage in move speed.
Please, please, please listen to the players, don't just tweak her numbers, give the whole kit a serious looking over, Cassie deserves better then this nerf to her entire play style.