My two cents....
100% on the tee and green. I use a solid line with a perpendicular set of dots It has absolute helped as I've dropped about 6 strokes off my handicap this year.
On the tee I use the solid line to make sure my club face is square. The dots show me where I'm aimed.
On the green I use the solid line to roll end over end on my target line. I make sure it is aligned with the line on my putter head.
Arccos says I'm playing as a 4.1 HCP putting and 10.5 driving.