That's not even close to the amout of snow ball we had back in season 2 or 3.
Snow ball does still exist however but it's not as hard as it used to be. It is slower and the difference betwen a player that died in lane and the player who killed him is very low right now. In top lane if you die, you can TP back to lane with 5 potions and you missed 0 CS, lost 0 XP. So basically you can have a lot of lane control even in a tough match up.
I'd call it "** Slow ball **" now....
It means what it actually is : a huge ball of snow, it is very hard to stop it but it takes a long time for it to be effective and harm.
The advantage is there, and it's very hard to undo it or to fight against it. It will give you an edge for a long time and maybe last the entire game. But you haven't won yet and you will have to confirm that lead in mid-late game if you want to take over the game.
" Snow ball " is a lot more explosive and dynamic advantage that gives you instant success in every thing. Season 2 or 3 was snow bally, season 4 and 5 are slow paced : Slow ball.
Now if you gain an advantage it is going ot be a long term benefit. In the past (s2 and s3) if you gained a lead, you could probably shut down the enemy in 20-25 minutes and win the whole game. It was very fast and very punishing. Now the game is slow and there is more room for mistakes. However if you are ahead, it takes a lot more efforts to finish the game now and win.
However as a season 1 veteran, I can forsee the outcome of a game in silver/gold Elo right from the start. I just judge the situation when we are 10 minutes in and it tells a lot about the game and its possible outcome. And the truth is that it is very hard to undo this situation and to turn the game into something more in you favor when you are behind. Silver and low gold players don't know how to come back from this, they don't know how "to close" a game and win properly either...