From what I'm reading/seeing about Assassins...
Kat will be somewhat more complex and less face-rolly to play, Talon wont be an insta-gib anymore in exchange for a better passive and superb roaming, Rengo gets a free QSS and a somewhat weakened ult utility, Zed will counter Jhin in a way, Fizz will be rewarded for proper vision and aim, Leblanc will seem to be less toxic by extremely delaying her damage, Akali will kill you slower and not immediately (efficient to charge the magic damage portion of the passive) ...and so on.
All in all, I'm kinda bothered on how much slower Talon's W ends up being...anyone can just sidestep or even dash out of it within the timeframe it gives. Maybe I'm exaggerating but...anywho. The rest of the champs I would say are healthier to play and react to. Leblanc might need a smaller delay on her passive and/or the small cooldown to actually be viable, but all in all, decent changes all around.