I have used the service in the past. I've met 4 people in person because OKCupid. As a man, I wasn't too worried about safety issues with meeting a lady. However, that didn't make me any less nervous. There were no love connections, but I have to say that I am glad that I met all the people. They were good experiences, and I felt like I had a decent amount in common with the people I was matched closely with.
I'd say, if you meet any person on there, absolutely make sure that the first date/meetup is in a public place. Drive yourself. Make sure that you can meet the person first and get a feel on the type of person they are before you have anything more private. I am sure you know this, but I just figured I'd mention it.
One thing to keep in mind also... This person may be just like you, or "us" here at this forum. Just another person struggling with SA and trying to meet people. You certainly want to be careful, but it's completely possible, and even plausible, that this person is really nice.
Good luck!