Two things, Listen to your boss, dont get fired for going against his wishes...
But yes QUALITY press releases help with rank there are not very many high quality services..PRWEB used to be one of them but last year sometime they got caught letting something hit the wire that mentioned the name of the Big G that was false, so I immediately dropped them and went with a different, more reputable (and more expensive) service.
The key of course is to diversify your links, use a service that really screens releases (they are more credible) and dont over optimize.