I was on a couple of the free ones just to see what it was all about. I wasn't seriously looking to date. But honestly, I wasn't impressed. It might be because they were free, so the quality wasn't good. People tend to put more attention and effort into something they've payed for. But in my experience, I just got tons of messages from guys who I have nothing in common with who's messages consisted of "Hi my name iz stan. i think u r very pretty/sexxy/stunning/*insert compliment*. msg me if u want 2 chat".
Maybe it's just a quirk of mine, but I'm not impressed when people don't use proper English. I know I'm not perfect, and I'm certainly no grammar nazi, but I feel like textspeak and not using proper punctuation is just lazy. But seriously, I got 30 of these in a day. The fact that I had absolutely nothing in common with about 98% of the people who messaged me screamed desperation. I put time into writing a very detailed profile about myself, the kind of lifestyle I live, my long term goals, my personality, and what I was looking for in a date. It was actually kind of irritating to me that only very few even brought up things we had in common and made a comment that proved they actually did read my profile and weren't just looking for whatever they could get their hands on.
Additionally, I got a handful of messages from men who only wanted sex. A couple were willing to pay me or be a "sugar daddy" in exchange for my companionship. One claimed to be a body builder and model and even sent me pictures of himself in his underwear. I got a couple a couple messages from lesbian girls telling me I was cute.
Anyway, that was my experience as a female. You may experience things differently because you're a guy and there's generally an expectation that men make the first move. My guy friend who made an account with me, who is by no means ugly, got very few messages in comparison to me. Another friend, also not ugly, nor unaccomplished, was very active in sending messages to women he thought were interesting. He got very, very few replies (perhaps because they too were being flooded with 30+ messages a day and being annoyed by it). I think if you joined a Christian one, you would be better off because you are narrowing the pool to exclude people who are Christian by label but don't practice and those who simply "believe in God".