I went on this site after my son found a nice woman who he's now been with for three years.
In the year I've been on the site I've had several coffee dates but only got past a one or two date situation once and we saw each other for three months before deciding it wasn't working for us.
Everyone I've met has been nice and looked like their pictures or better. A few encounters never got past the messaging stage but for the most part they were OK experiences. You will get messages from obvious scammers but all you have to do is block them.
After a year I see many of the same faces so after having decided they won't work for me it narrows the field down considerably and I lose interest for awhile.
I have a woman friend on OKCupid and as I had suspected it's a whole different type of experience for a woman. She showed me the types of messages she's received and it seems for every guy who seems sincere there are 10 smarmy or downright creepy guys. I can't believe how douchey some of those guys are.
My son is very happy though and I think he and his girlfriend will probably get married.
An update: I met a woman on okcupid about 5 months ago and things are going great between us. I think this one may last.