Go TB all the way...
- US T2 Aircarft Torp hit quite hard. They can cripple 100 bulge and 0.2 belt with only 5 or 6 torps hitting center.
- you can hunt SS and kill small ships. With DB its difficult to achieve this
- Also DB can't penetrate on UK Armored BB. US DB are fast but they can't really hit hard
US are primary to FW, and you should consider using 1 Scout... but the best config for US should be 6 Ftrs 1 Scout and 1 TB.
Don't mind about XP, since you will get most of your XP by FTRS