Tom's right about the positioning of the device. Keep it low down between your foot arch and your ankle knob, and strap that thing on tight!
I have my groundie hold a little tension (20-30 lbs straight down) on my line for the first 20 feet or so. It is amazing how much of a difference that makes in getting started.
I also never thought a pantin would fit on over a pair of spurs, but I was wrong. A little adjustment of the strap, slid it on, and I ascended up the rope to a dead section of tree and started spiking away...