I had an '11 and a '15 HD 6.0 and I thought it pulled very well. I have weighed it from time to time and combined 31K. I took them over my passes (except Teton) and was very happy with the performance of the 6.0. Never pulled a half ton to compare. I would just say that it might be that skid steer your pulling weighs more than 5K. There are of course many different sizes but only the smallest models weigh 5K. My tracked machine weighs over 10K (CASE TR340) and my wheeled machine weighs 9K (CASE SV340). Perhaps that is the reason the 6.0 doesnt feel as strong by comparison.