I, too, keep a string tied on the end of my stabilizer. It tells me what the wind is doing right at me, but it does not tell me the path of my scent say 50 yards away. Whether you use freebies like seedpods or those little puffy fiberglass things, they will tell you what the air around you does with the wind. I have been amazed at watching the path of ofslight but constant breeze.

I have experimented by spacing out the wind floaters over time have been amazed at the exact replication of what seems to be a random breeze.

To know that your scent will cross an exact place is VERY helpful in knowing how close to let a deer walk. If nothing else, it helps with your confidence in the same way that a range finder does.