I must agree that quality link exchanges are helpful for both getting better link popularity+PR and for getting traffic from the sites you trade with.
there’s no doubt that the directory type of link trades where links are buried 3-4 clicks (or more) from the index page and there are 100 links on that page will send you no traffic but will somewhat help your rankings.
on the other hand, when exchanging links with pages that are 1-2 clicks away from the index page using a visible link and contain a reasonable amount of links per page. Rankings and Traffic will get a more significant boost.