I'll give my 2 cents. This is my own experience. I played the wind for years. I still do on certain types of hunts like stalking with trad equipment. That is to keep things trad.
I had a season a few years back where in spite of doing my best I could not hunt without getting busted for scent. Time after time after time. No matter how well I set up, how I tested thermals, prevailing winds, etc, thirty minutes after getting settled in the wind would switch. It really did not matter what wind I needed. If I sat in some of these spots for an hour I would get wind from all points of the compass. Why not go somewhere where the wind was steady? Simple, no deer there. For some reason the deer hung out in these wind tunnel spots. Imagine that.
Now keep this in mind. We have very low deer density so it's not like if one busts you in the morning all you have to do is ride up the road and get on another deer. When there are 5 deer per square mile you better make it count when you can find where they are and not blow it because you may not see another deer for a week or two.
After that season I found some Scentlok on sale and bought it. It was less expensive than most of the Walmart stuff at 75% off. I bought a set and learned about how to use it (I emailed John and he sent me all his info) and the next season, under the same conditions, and the same deer, I was going unnoticed. I've had mature does downwind often enough to say that I am convinced it works. If someone else flatly refuses to believe it, that is cool with me.
I keep mine in a bin in my truck during season, I change at the truck (no big deal) and never wear it pumping gas, going in a store, etc. I wear rubber boots that get put on at the truck and taken off at the truck before leaving. I deabsorb it as needed. It's pretty simple.
Case in point. Early this season I was hunting off the ground in my Packseat. I was set up covering a narrow creek crossing that led from thick bedding to a small stand of white and red oaks along a creek. I had the wind hitting me in my face. Everything was perfect for where the deer should come from. I heard footsteps in the leaves behind me and turned in time to see two mature coyotes trotting by me at 7 yards straight downwind. They were doing that trotting gait they do when they are just happily going along without a care in the world. They trotted right by me and never skipped a beat. This was on the ground. There is no way my scent would have drifted over them, and they were 7 yards away.
Like I said, I have my system dialed in. I am not as meticulous as John is. I can say that I have not been busted by a deer for scent since I started using Scentlok. I have had different reactions from hunting hogs on the ground. They seem to catch on and have zero tolerance for scent. I feel that deer operate on a sliding scale in regard to how they tolerate scent. Big land deer who never smell people outside of hunting season are on one end of that spectrum and the park deer that will eat out of your hand are at the other.
Anyway, that's my take on it. Having a system that eliminates most of my scent has opened up the areas the deer live in for me, areas that were off limits before. Do I enjoy putting it all aside and play the wind from time to time? Sure.