We use them on the family farm. It's about 150 acres of timber and 25 acres of pasture, surrounded by large tracts of cutover and 8 to 10 year old pines. There is no doubt that they attract more deer to a given spot than would be there without. Having said that, I haven't seen a whole lot of difference in the number of deer coming to them as opposed to what comes to rye grass plantings. The main advantage of feeders is that you can put them in places where you can't plant grass, like in the timber.
We've been feeding for several years now and have had cameras on the feeders the entire time. I can count on one hand the number of decent bucks I've got on camera during legal shooting times. The does, fawns, and small bucks visit the feeders almost every day, sometimes in the morning, other times in the evening, and sometimes at night. But I don't see many bigger bucks until after dark. If you're meat hunting though, they will help you fill the freezer for sure.
To be honest, we're thinking about taking ours down because of the CWD concerns and that we think they've made the deer more nocturnal than they were before. All of ours are the metal ones that Academy Sports sells. We've had very good luck with them and leave them out year around, although we don't always keep them filled/on.
I've got another place I hunt that is about 800 acres of mostly crop fields, with a few cutover thickets and small tracts of timber shattered in. We don't feed on that property at all and I see way more deer and have better luck there with bigger bucks too. But there are a lot more deer on that place.
Last edited by KoolBreeze; 11/12/18. Reason: typo