In the past use to get around 400 reciprocal links per months for several of our sites. I generally look for reciprocal links to be relevant, no hate or porn sites, no more than 50 links on a page, no dynamic/query strings. If it has a good page rank all the better. I do see that a large amount of these types of links is rewarded by Google .. I will say that one has to cautious of bad neighborhood links...If sites which holds your links are banned ,this can put your site in a difficult position , so have some basic criteria before choosing one..