So, I have the Ck2610 HST, and I absolutely have ran out of HP at times. To do certain things, you need a certain speed, so, just doing it in low doesnt work. Even down to climbjng/backing out of a deep ramped cut, yes, need power, traction, and speed, as low doesn't give you any momentum. Pulling a 7 ft chisel/field cultivator/all purpose plow. 6 ft box blade, filled, you can loose power before you loose traction; but you dont want to run a box blade in Low either.
So, yes, someone will rightly point out, your trying to do too much with too little of machine, and that is correct; but to say 25hp isnt a limitation, is also incorrect