RE: How important is sent, really...?
Scent control is very, very, very, important. If you have hunt deer very much you would know that. And if your talking mature deer then you will not kill them very often if your careless with your scent. Use unscented everything and play the wind and you will be much more successful.
Cover scents are a waste of time. Every scent has its own molecular finger print. Thats why a deer can smell where another deer stepped many hours before with no trouble. The smell of the dirt, weed, corn stalks, leaves, etc. is much stronger than the spot the deer stepped but the deer can track the other at a fast pace with no trouble. This is also why a dog can smell a body on the bottom of a lake or in a huge pile of rubble or drugs hidden in all kinds of stuff.