Depends on the term, but alot of difference. I noticed a huge difference on one of my sites when it moved from 4 to 1 on MSN only
I've read different reports but some say that the top spot gets 90% more traffic than other links that come up on the first page of results.
Most people don't go past the first or second position. On occasion when Im looking for something specific I've went 10 pages back, but I doubt that happens much.
it sometimes depend if the top sites are spam or not. but if it's legitimate, then you would expect people not to slide further down the list.. note though that sometimes 10th place beats 5th place in traffic.
If your site has a catchy page title it might catch the users eye. Maybe not for a #10 ranking, but a 4 or 5
On Google, #10 shows up on the bottom of the page, so maybe before they go to click page 2, they see your link and may be interested in it. I think a #9 or 10 position might do better than a 7 or 8... So I guess it's better to have "Keyword - short 2-3 word description" in the title instead of just "keyword"?