While it would be a sweet rifle, I personally don't feel the 25GT would have enough HP to make a medium/longer range hunting rifle.
I have a 22GT and love it for varmints. I have loaded for a 6GT too, and a 108-115 really takes it's toll on velocity. I think a 133-135 would really slow it down too much for my tastes for hunting out west. But for areas where hunting shots are 600-700 max, it might be a viable option. The extra 200fps from a 25CM would really help though.
Great advise! Speed kills.....no speed equals runner, nippers, and lost dogs....