I hunt from the ground quite a bit during the early season. There are some advantages and some disadvantages. I find early in the season I can get away with it a little easier because of better cover and the deer aren't as spooky.
Advantages are, wider kill zone to shoot at, if a deer is sighted you may be able to sneek in on it, you don't have to hunt the same spot every time you go out, and its safer.
Disadvantages would be, easier for deer to find you, scent, when a group of deer come in but you don't want to shoot one of them because your waiting for the big one, it's very hard to have them stay around very long with out them finding you. And once they find you they'll make a big stink and then your chances of having the big one come around are slim.
I've killed a quite a few deer from the ground, but I get busted by them alot more when hunting this way. Not every time, but more from the ground than I do when I am in my tree stand.

The spirit of the woods is like an old good friend