I have decided to release a couple press releases. I am only targeting 3 keywords. Is there a benefit to write a unique article for every different website?
of course, and the same of article submissions too at least make sure the title and first paragraph are unique
I think that's unnecessary. Why would you do that if it's okay to submit the same press release article to the distribution sites?
Writing unique articles is always good if you have time to write. It's better to make different versions of the article by just altering the sentences (using synonyms of the words.)