I've noticed that different brands seem to have different characteristics in terms of arc, rotation speed.
Also noticed that some cheapo brands are very flexible thin plastic. Because of this flex, when you pull the flasher through the water, the resistance changes the contour of the flasher at times resulting in erratic operation.
I like a stiffer plastic flasher that will hold it's shape.
I think the original hotspot with it's gnurled indentured metals strips on both sides affects the rotation speed nicely, as opposed to flashers that have shiny surfaces or shiny tape on both sides.
The actual thickness of the plastic flasher affects the rotation and "tracking" characteristics of the flasher.
If you have a flasher with one side that is completely different from the other side in terms of finish (eg:- one side is completely rough-surface glow tape and the other side is silky smooth paint etc).....this will affect the rotation because of the two different surfaces.
Thin,light ,"flexy" flashers will turn faster and be more erratic in tracking.
I have a couple of old Hotspot "Super" Flashers......these look like reg Hotpots except they are thicker and heavier.......they roll slower at troll speeds.