Once you practice a little, banana flick is higher percentage, but not as troublesome to better players. The banana flick doesn't produce a lot of topspin or pace, it simply is a one way to safely receive the serve and make a little of an offensive shot. Often, just a little offensive is enough to win or set you up to win the point. At the least, it is a stronger option than simply pushing the ball back vs a powerful and consistent opponent. The regular flick is a lot more dynamic and troublesome, many more options heavy, medium, no-spin and any amount of pace, but reading spin to the letter is essential. With banana flick, reading the amount of spin isn't so critical, the timing of your sideswipe acceleration is the important piece. That takes a little practice, but you can handle many different spins with essentially the same shot.