How good is sheet to tiller steering

How good is sheet to tiller steering?
Motored out due east into a westerly Turned SSE at the red dot.
Took until the yellow dot to set up the sheet to tiller gear from scratch.
Sailed to the green dot (trawling) and turned back on a reciprocal course. Took until the blue dot to completely reset the rig for the alternative tack.

The red line is the preferred course in both directions. The yellow diagonal lines show the point of the most deviation from course. That was 250 metres.
Total distance sailed was close to 10 miles (5 miles each way). Average speed 4.5 knots.


Two of us aboard, one to use the gaff hook if we hook a big fish and the other to reel in. The tiller pilot of course uses electricity and on top of the has an irritating noise, so I though it would be worth while giving sheet to tiller steering a go.
The boat is 25 foot with a fin keel, skeg hung rudder and typical underwater shape from 35 years ago. The control lines are no more intrusive than the tiller pilot and we could pull in a 60 cm Spanish mackerel with no hindrance.
You can see that the course is dead straight where we were using the tiller pilot (red to yellow and then green to blue) then slowly yawed along the course.
The tiller hardly moved until it was enough of course to power up. Then it only moved 5 cm or so either way.

This was third effort at setting this type of steering and each time I learnt something for the next try. The total cost was $30.
Am making up a video.
The verdict? Fantastic