Well if you've ever seen these Indian sites which only exist as patsies for triangular home page exchanges then you might not agree

Actually the home page stuff is a lot better since you've got more to give and thus can get more back. Other than buying links if you want PR back you've got to give it and very few sites indeed have PR in links pages. However this doesn't mean that the no PR for no PR swaps aren't valuable, they are, but it's due to the sheer number of them that you can do. No page has zero PR, it's just below 0.50, and perhaps very below, but every link has some juice behind it. So while you'll be able to squeeze a few good home page swaps in there, you don't want to pollute your home page too much and you want to have most of your links in a directory of sorts.
Ken
http://kingcobrapoker.com