Reciprocal Links - when to say 'Yes!'

[nigelaxis]

Reciprocal links no longer have the value they used to. On this basis, can we have some specific rules on when its a good idea to swap links. I have been getting some conflicting info on this.

For instance: Only swap links if....
1) There site is of a related topic. (good keywords), and
2) They have equal or higher PR then your site, and
3) There link page has less then 40 links, and
4) There link page has PR, and

All of the above or reject the doing reciprocal links. This is my example......but please could you let me know your rules for exchanges.