Your headspeeds should be OK for sport flying:
138 main /14T pinion = 9.86 : 1 ratio
2580kv x 11.1v = 28638 max rpm
28638 / 9.86 = 2904 rpm on the head (w/o calculating ~10% loss)
2904 x .9 = 2613 rpm of true headspeed after losses w / 14T
Try increasing the throttle curve in the radio until you get the headspeed you want. Also try running on Low Gov mode too, and mess with the throttle curve too, until you get what you want.
Is the red light on the CC25 coming on to indicate it's at full throttle?
Do you have a tach, or are you just winging it?
What Lipos are you running?