I haven't used it. I have used the CK20, but it was a gear model, and I own a CK25 gear model. Also two range. While three would be better, I haven't long for anything else. Maybe the gear is different. I do loader work by switching from 1 low to 1 high and it works good for me. I push into the pile in 1 low, fill, back out, stop and switch to 1 high. This is more than fast enough for transport.
I would say if you are working on hills, and want to go fast, it might not be the tractor for you in HST. If you don't have a need to speed up hills, then it'll be just fine. Gear may perform better on steep slopes (wrt to travel speed).