I joined recently so it may be too early to review, however, with that being said, I can review a few things with confidence.
1. There are gold farmers on JC, most seem to be Chinese in origin. Usually they will try to get your email and after a few email conversations they will try to get you to sign up on fatemeet and some other site.
2. It is VERY hard to get a response. People, keep your expectations LOW, or you will easily be crushed. For me it doesn't matter if anything comes of JC or not. The fact of the matter is JC like any other form of online dating can be super unforgiving.
3. The site is fairly simple and easy to navigate. Naturally it helps to be a paying member. I paid for a full membership, either way women will cost money at some point.
4. Again keep your expectations LOW, and I mean VERY LOW!
I personally can say with 100% confidence that I will not be finding a Japanese girl here, but that's the reality of online dating. Your milage may vary, good luck!
Beware of fakes and gold farmers.
Nick does NOT recommend JapanCupid.com to friends/family