Based on what you want. Summer Salt is one of the best attack Fighters in the game but she is rather weak in a defense team. Overclocked is above average on attacking side due to her unblockable Precision attacks, but she is more about being a good defender.
If you mostly play Prize Fights, then Summer Salt totally wins the competition, defense teams are not that meaningful there. If you want to improve your Rift Battle game, then both will be useful in the long run. I would say that Summer Salt has an advantage though, as many top players consider solid attacking force being more important than top-notch defense.