R's cooldown is longer and the warning indicator's range is increased. Also Rengar's prey will always have a warning indicator if he's within range, even if he's hiding behind a wall. Obtaining the giga-rare 'Head of Kha'Zix' gives Rengar more vision while stalking in brush.
While Rengar's Thrill of the Hunt is usually quite fun for him, we've seen he can be a little frustrating to play against - particularly in the early game when he's roaming everywhere, and in the late game when his prey is usually dead as they see the warning indicator. The short-form of this context would be that we want Rengar's ganking power to... Slow Down!
BUG-FREE KITTY : Fixed a rare bug where Rengar would not leap from a brush if he recently flashed into it
Head of Kha'Zix
NEWDON'T ASK HOW THIS WORKS : Rengar now has increased vision range while in a brush with the Head of Kha'Zix
R - Thrill of the Hunt
NEWX-RAY CAT FINDER : Warning indicator now appears even if Rengar is in the fog of war while stealthed. In other words, if Rengar is within 1250 range of any opponent while stealthed via Thrill of the Hunt, they will be notified.
LONG RANGE CAT FINDER : Warning indicator range increased from
120/95/70 seconds ? 150/110/70 seconds