After the rengar changes
The Q Nerf and Buff:
Insignificant really, these changes dont mean nearly as much as the other changes
The Ult Indicator:
This is much more of a big deal then people realize. The increase in length means rengar can't just ult through the lane, not be seen by a single ward, and kill the enemy. He now has to gank through the river with his ult. This means there is now a chance of rengar being seen by wards (mostly talking about bot lane and top lane, mid lane will still be easy to gank). If rengar ults through the lane, the enemy will see you comming because of the increased distance of the indicator, he/they will just walk back to their turret and the gank will be unsuccessful quite often (especially at bot lane).
The Bola Nerf:
This is the most annoying change they could have done and i really hope they revert this. That .25 second delay on rengars bola is so dumb and clunky that it should not even exist. The others nerfs, i can deal with, but this change makes me miss my mid leap bolas so much because of this stupid buggy mechanic they had to throw in. So now along with ganks by rengar being harder, and having the 3rd largest cooldown on his ult at rank one, there is also no guarantee that i can even CC someone down and pick up one kill because riot to do something about the one shot mechanic. There had to be another solution other then the bola changes to stop rengar from one shotting (I never even did the one shot most of the time, not because i dont know how or i cant do it, just because it requires rengar to be extremely fed AND his Q has to crit. If his Q does not crit it can not be an authentic one shot because chances are you will not be able to one shot the enemy in one rotation.)
for those of you who dont know what an authentic one shot with rengar is, here is a video