This is definitely never my "primary" source for SEO. It is mainly just an addition to the currentl link building strategies already in place.
My main concern was the fact some individuals in the office don't understand SEO very well and wanted me to send our our PR's multiple times. I think they misunderstood my explaination at sending them out at the most once per week and using different sites to do this. I really just wanted to get another solid answer of "No" to reassure myself.
I do like your idea of just putting the PR on the site and letting people link out to it. I am planning on converting the PR's into PDF files and then putting them on our site as well. Problem is, I don't want to submit the same release 5 different times, then put it on the site. I'm more for the submit once, post on the site for visitors to view.
To be truthfully honest, the competition we have is doing a lot of this for SEO purposes. They are trying to rise up organically as our industry prepares for a possible change in the market. I see a consistant number of companies pushing out PR's, with lack of purpose other than to help them with backlinks. Once again, not primary, but definitely part of their strategy. I think this is the main reason my co-workers feel that they should do the same, which I am telling them, "No, lets put one out per week at the most... Maybe just 2 per month."