They are fun. I like using them more to see what is around before the season starts or after. I just like seeing stuff on them. I have captured some cool stuff with them. I hunt where I hunt because of sign, food, time of the year, travel routes........
The only advantage I have gotten for me is figuring out a few areas were totally nocturnal for activity. I guess that saved me some hunts to figure that out. I have also confirmed what I learned from on stand in one spot I hunted for a few years, and that was that deer only came through at night or in the middle of the day in the pre-rut and rut. I know that happened a lot from experience watching the area all times of the day during the hunting season, but it was interesting to see it was very consistent day to day that time of the year and much of the rest of the year. I always figure there was a tendency for that behavior the 6 or 8 days I hunted it every year, but I had no idea just how consistent it was.
I must say I have been surprised a few times on what all I have seen on them that I never know was around. But, as a meat hunter, I shot what the good Lord puts in front of me. I only get picky if I am setting on my last restricted buck tag and the freezer is about topped off. By that time all bets are off with the rut in full swing. What you knew was around just a couple weeks or so before may be dead, moved off, or totally unpredictable.
I don't like to have them on my hunting spots for deer. I think they work real well on turkeys, bears, and people. I do think the deer figure out they are there even if I am real careful about not pressuring the spot and check them rarely. I think it is the IR light that attracts them, and then they smell some scent on them. I almost wonder if the flash is better than the IR light. Most of the deer that seem to spot my camera and become aware of it do so at night. I have been thinking about not using the light and setting it for daytime hours only.
I have found if I have a major scrape or other attractant, they will come in a lot and not be spooked so easy if they are distracted. It seems to me they move off trials with them when they wonder through slow and cautious and then pick up on the camera. I have seen deer move off trails with them even if the trial is right on top of an active human area where they would expect to see and smell people.
I am starting to think more about putting them much higher off the ground out of nose reach and line of sight. That and also putting them where they are obstructed and harder to walk right up to.