94 version give bigger hits especially base game and free spins
96 keeps more steady balance, hit ratio better and bonus more frequently and pays slightly better but more often 100 - 500x base game and free spins wins
The 94% version makes hitting 1000x easier and quicker.
I also prefer 94% however 96% on Pompei Megareels and ZVH - Trust me you will see how good these two play on 96%