All of my comments are limited to whitetail deer as I never baited anything else. I grew up hunting in PA where baiting is illegal and looked upon as cheating. I now live in TX where corn is actually a verb. From "ethics" standpoint, I don't really see much difference between baiting or hunting over a planted field of some sort. Actually, I believe a planted field or natural bait is much more effective than a corn feeder or something of that sort. That being said, here are what I consider Pros/Cons:

Pros:
Can give you a chance to really look at an animal. This is important to me because of state mandated antler restrictions. Also nice to help age deer.

In TX, where everybody baits I believe it helps keep deer on property vs leaving for somewhere else that is baiting.

Can augment food source for wildlife during hard times of year or drought conditions.

Gives you a good place to put up a trail camera to see the mature bucks that never come out in daylight hours:)

Cons:
Something else to maintain/worry about. If you are using a feeder count on it not working so make sure you put it in a place where you are not soley relying on it to "lure" deer in from somewhere else.

Can be expensive whether it is a food plot or loading a feeder

For some guys, they can be overly reliable on it and not hunt other areas.

Lou