I say it's both. You have to control your scent as much as possible AND play the wind. I never hunt a stand that the wind direction is totally wrong just because I think my scent free regimen will prevail. It WON"T. It is my opinion that you try to minimize a buck's sense of smell. I don't think you can completely beat it. The silly marketing campaigns that say "forget the wind" are just ridiculous. Bad advice in my opinion. I personally am 100% convinced of the benefits of using ozone to mask human odor. Notice I didn't say eliminate human odor. I can tell that deer still smell the ozone, but it isn't alarming to them. And, this will sound crazy, but deer are curious animals. I have had deer smell my ozone and come closer because they are curious as to where that smell is coming from. Yes, I have had both bucks and does put their nose in the air and suck in ozone and approach my stand trying to figure out what the source of the ozone odor is. Now, I'm not saying ozone "attracts" deer, but I have witnessed it with my own eyes that they will sometimes be curious about it.