This is a HST machine? If you can use the pto hp for a wider snowblower, mower, tiller, running a round baler, disc bine, its a good idea. Or you're at altitude.
My take with a HST for ground engagement is that you shouldn't run it at much lower than PTO rpm, so the revs are going to be pretty close all the time anyways, and I'd rather have the engine start to strain and let me know I'm finding the limits rather than breaking a front axle trying to lift the whole gravel pile with the loader, or burn out the HST trying to pull the box blade or plow in mid range, because it has the hp for it.
Is anything else on the drive train or cooling system up graded with the extra HP?
My tractor was the same machine for 40-45-50hp versions except the 50hp got an an engine oil cooler. The HST, axles, hydraulic fluid cooler, rads, were all the same, so I figured the 40hp would be easier on the whole tractor, and I'm not going to wear out the motor in the 3-4000 hours I'm ever going to put on in 30-40 years.... All 3 engines would run basically the same rpms anyways.
For a geared machine, I think the turbo's and extra hp is better and if your can't downshift on the move, the turbo is great for just adding more torque if you need it, and you can run lower rpms if you want, the trans doesn't care unless your really lug it.
