Which one do you prefer and why? I have not used a feeder in a long time but the last time I used a spin feeder it just dumped a pile of corn out on the ground till it rotted. I'm looking at getting a couple feeders to put out and I'm kind of leaning towards gravity type. It just seems to me like there would be less waste. But how long does it usually take deer to learn to eat from a gravity type feeder?