I would send it out to as many places as you can.
Press releases are limited with
seo as most sites do not allow anchored links. This actualy put's them in "contains URL" catagory.
I use them for High traffic links and to diversify IP addresses linking to sites.
One well written press release can bring loads of visitors and sales. But the quality of the links are not as good as articles overall. This is the average results, not an absolute rule.
Remember, an Internet Marketers greatest challenge is to stay in a groove without creating a rut.
Don't get stuck in a rut.