Jon, I didn't know you could turn it off. Do you remove the fuse or is there a hidden switch?
John,
Some of the mid production 3.7's came with a bought in PAS motor that was speed sensitive & could even be fine tuned, yours may have that hence you would be fairly happy with the feel as the assistance reduces with speed
MMC then binned that supplier and changed to a fixed motor, I have tweaked the feeds so that I can switch off the circuit that triggers it, not the main feed as that's 30amp, nice neat illuminated switch on the dash undertray so it can be selected 'on the fly' if you're parking
