I find the quality of the Road vs. the geometry of the suspension/drivetrain affects the quantity of torque steer experienced.
I (am lucky enough to) drive country roads every day to work, and find the variation of road 'quality' makes a hell of a difference in how much my Cup will jerk about. On some parts of my drive in, the road is of good quality and more importantly is flat across the whole of the carridgeway. At this point unless I'm driving like a thing possesed, the torque steer is almost negligible up to 3/4 throttle, then above - the tug on the steering can be felt. On the other hand, other parts of my journey involve minor B roads which although have just been surfaced, roll and undulate like a small mountain range. Here anything above 1/2 throttle involves a tight grip on the wheel as each bump changes the geometry of the suspension, and hence the quantity of torque steer which can be slightly annoying, but also entertaining as well!
This proportion of torque steer will also be affected, as already said, by worn bushes, ball joints, and unsymetrical situations with tyre pressures and tread wear.
I suggest having it looked at/tracked, and then grin and bear it, unless you fancy shelling out for a
CLIO 172/182 QUAIFE ATB DIFFERENTIAL or similar.......yes look at the price!!!