In the interest of a balanced view, I'm 5'11" and 190 lbs, and I find the H125 really quite manageable. It fits right in with my other magnums, points quickly and lines up nice. A true hunting gun.
If i could mod it to get close to the 125 power id swap out the barrel for a 25 cal
Barrel last I knew was about $80. The gas ram you'd need to boost that power would cost you another $45. Now throw in the cost of a high pressure hand pump, Hatsan fill probeand the adapter to attach that probe to the fill hose, plus the shipping to get it all delivered to you. After all that, hope you can boost the pressure in the ram enough to get to the power level of the 125 which has a bigger compression chamber and longer barrel to aid in the extra force it takes to cock oneAdd a bit and you could just outright buy a 125 and have the power already built in.
Got it back together. Clean relube... Shot it 20 times to get excess moly paste out. Then got crony out, had a weird high of 784fps to a weird low of 699. Then it settled in between 765 to 755 fps over 20 more shots