I prefer tree stands (aka deer stands), unless the weather gets bad.
Tree stand guys chime in here, but it has been my experience that deer are not very interested in stuff going on up in trees. However, stuff on the ground sure seems to get their attention. Feral cats and coyotes seem to notice me in a deer stand from far away. Deer seem mostly oblivious, and when they do notice me they seem to be more perplexed with trying to figure out what that thing is in the tree. Deer seem more easily spooked by stuff on the ground.
I've done blind hunting. While blinds generally conceal drawing a bow, or moving your rifle around it can also be harder to see approuching game, whereas tree stands give you a much better view.
Tree/Deer Stand
Pros: better view, deer seem less skiddish
Cons: more exposed to both elements and the eyes of prey
Ground Blind
Pros: modest shelter, more concealed
Cons: limited view, deer more interested in ground action
A final plus for tree stands, when wearing blaze orange tree stands also make you more visible to other hunters, which allows them the steer clear and improves safety.