The one grip which actually significantly affects performance.
This grip mounts the launcher to a spring-loaded carriage which is pulled back by the friction of the ripcord being pulled from the launcher, then as soon as it leaves the launcher jets forward, pushing the Beyblade forward on release allowing for east sliding shots or even launches aiming to collide with opponents mid-air. There is also a switch to lock the launcher if this is not desired, and the carriage can be manually manipulated to charge or hold in place as well.
In theory, the gimmick could weaken launch strength as pulling the launcher back with the ripcord reduces the relative velocity of the ripcord to the launcher, however with EZ Shooters and the Power Custom, a strong enough blader is already likely to be able to pull about as hard as the launcher can handle anyhow, and for attack one can already reach more than enough power to struggle to avoid self-KO.
Manually cocking the slider, however, provides a boost to launch strength if released while pulling the winder, and can allow for very easy "gattyaki" (an apparently non-existent word the WBO uses to refer to launches aiming to collide with opponents before they hit the stadium). This method is more difficult but also arguably more rewarding.
Overall, a nice little utility, of not a necessary one.