I have a DK 45 with the 12/12, and the lowest speed on it is amazingly slow. I don't till with my tractor, but if I did, I'm sure the creeper feature would be very handy.
I do use the low gears for when we are picking up hay or tobacco and loading on a trailer (pulled by the Kioti) and we don't have a driver; we will put the tractor in a low gear (usually like Low 2 or 3) and just let it put along while we load. Occasionally we have to reach up and steer the tractor, but it's better than having to get on the tractor, put it in gear, mover 50 feet, take it out of gear, get off the tractor, load stuff, repeat, repeat, repeat....