Over 75 degrees F...anything composite. Every manufacturer has a great bat with great pop. It all depends on the batter. A smaller girl will do better with a composite that has a little bit of flex in the handle where as a larger girl or power hitter will do better with a stiffer end-loaded bat. That being said, a girl with a great swing will have far more success at the plate and hit the ball further no matter which brand of composite they use than those that don't have good swing mechanics.
Tested each popular bat this year and we prefer teh Xeno. From the first swing it is hot. No sting and good feedback for hitters with its unique sound.
Dont get a good piece of the ball and it tells you.
Xeno smallest bat is 30/20 some of the other bats also only have “larger” bats too. You are probably going to have a hard time finding a single brand that will be best for the smaller and larger players, there is a big difference in players sizes and strength in 10U – 12U and MS.
I like the XENO too but there is going to be some 9 YOAs that should not be swinging a 30/20.
Xeon is hot, but has a smaller sweet spot than other bats in similar size. DD uses both a Xeno and Synergy 30/20 and does well with both. Love how the sound of the Xeno catches the attention of the umpire and they check to see if it's broken.
This weekend out pitcher almost had her head taken off by a line drive from a hitter using a Xeno. I've pitched to my DD and she about killed me with her Xeno. The ball screams off the bat when hit in the right spot.