Boss buck is nice but my favorite are the stump feeders
If you have pigs they will play soccer with your stump feeder. Boss bucks are great but like other have said... once your deer get used to it you will constantly be filling it because they will assault anything that's not restricted.
If you go gravity go with Boss Buck. They are the best for the money that I have found. There are better made ones out there but they are way more expensive as well. I'm pretty sure you aren't looking to drop over $1K for a feeder (I know I'm not).