I've read some online reviews, but just curious of any your daughters have experience with the CF9 balanced (31/21). My daughter had the 31/20 CF8 last year and we found it to be very hot, just not durable.
I believe the -11 bats are hotter because they are made with thinner walls to save weight possibly? My DD has used the -11 and it was hotter than her -10 cf9. Could be hotter because it's lighter. Who knows really. I can tell you she loves her cf9 and we have had no problems with it. She hit the new cfx last night and didn't like it. She said it vibrates when you hit it.
My daughter had a CF9 31/20 that she busted in a month. We replaced it with a 30/20 and no issues since and still quite hot. When she grows out of the 30/20 CF9, we'll be replacing it with a 31/21 CF9.
Just picked up the CF9 31/21, daughter hit a couple of the tee and soft toss, absolutely loved it. Said it felt more balanced and lighter swing weight than the 31/20 CF8... go figure. She said it felt very smooth and like the ball was flying off the bat. Thanks to everybody for responding.