Just seeing deer gets any hunter's heart pumping. That's why it's so hard to resist sitting right on a green field or crop edge -- you definitely see more deer.
If you're meat hunting or are taking a youngster out, watching a field can be very productive. If you're hunting a bigger buck, however, it's probably not your best choice. Except during the rut, bigger bucks will usually be the last deer to enter a field, and many times they'll wait until after legal shooting light.
Mature bucks will often have their own trails heading to such green fields, so if you've seen a buck enter a field just after shooting light, mark the trail in your mind. Come back during the day, backtrack the trail and look for an ambush point somewhere off the green field. An excellent choice would be an oak tree or other food source where the buck will have a snack while waiting for dark.
You won't see as many deer hunting such a stand, but the deer you do see could be worth the wait.