Northern,
The major difference would be the fact that you are able to kill the vast mojority of the deer that you see while gun hunting while you aren't only able to kill a small precentage of the deer you see while bowhunting. But, for some data to back up my opinion why don't you go to your states DNR website and see if they give a break down of kills. In my state although bowseason is 4 1/2 months and gun season is only 2 weeks there are roughly 100,000 deer killed during gun season compared to less than 20,000 killed during the 4 1/2 month bowseason. Also, hunter success rates are close to 20% points higher for gun hunters. In my mind those numbers in themselves speak volumes.
Sorry, but I am not buying that arguement at all. Here in Minnesota the sucess rate or rifle hunters in 2003 was 39.7%. The sucess rate of us archery hunters was 35.7% during the same year. In Minnesota rifle hunters kill the majority of deer because they out number archery hunter by a huge margin. Both rifle and archery hunters could probably kill lots more deer if they shot at everyone they saw but you know that isn't the case. Seeing deer is not harvesting deer.
You can find my data right here:
http://files.dnr.state.mn.us/outdoor...vestreport.pdf