Silver scrub ADC main chiming in here. I got to play two games on her today, a normal and an ARAM.
The normal game went okayish. Her lane phase was fairly fine but that's only because the enemy Varus did not abuse his range advantage to bully me out. However I noticed that her E lock out feels really really really bad early. To give an example, I was in a jungle fight and had to dodge a Q from the enemy Bard jungle. I pop E and juke it, feeling really good about it. Until I try to auto and realize I still can't and he just last hits my ass because we both had one hit of health left. Early game, the lock out time feels like an eternity and on a champion with such a short damage window due to her range being so short, not being able to attack feels miserable. I fell behind and just did no damage as well. I went a more AP/on hit build of Nashors, Wits End, and Rageblade but found myself just doing no damage until my passive popped. I felt so useless unless I got all four or five autos off because Rageblade. I got flamed by my team a bit and did tilt, selling my items and going crit but even with IE, PD, and a Zeal I felt like I did not do nearly enough damage to be any real threat.
The ARAM game. We lost hard. The enemy had a Caitlyn and that felt really good to fight. At one point I literally said to my friends in teamwork "ADC Thresh has 50 less range, free scaling armor and damage, and lot more utility than Kai'Sa. I'd rather be AD Thresh right now." And that should tell you all you need to know about her in ARAM. I think I landed less than 50 autos on champs that game.
I really do think her range needs to go up, at minimum 525 but probably to 550. She doesn't have Sivirs range or wave clear and she doesn't have Lucians mobility without a damage lock out. She just doesn't compete with the other 500 ranged marksmen. Not even getting into everyone else out ranging her.
