These pads will definitely improve your game. That doesn't mean you will get less deaths, because it has to do with other factors as well, but it will improve your number of kills. I managed to get used to them after a couple of games, and you will probably only need around that. They are soft and comfortable, and your thumb will no longer slip during a gunfight.
However I did find this product expensive. I bought these thinking I might lose them, but once they are attached to the analog stick, it is very hard to take it off( but it is possible!), which means a pair is enough if you are only planning to use one controller.