I used them for a few month, but not doing it anymore. My reasons:
1. A lot of signal providers, who start with account of 10-50 USD, they make 'miraculous' one or two trades and suddenly their performance is 1000+%. They are not filtering those 'traders'.
2. You have no feedback about the system, if your signal provider is not trading, you have no chance to contact him/her to find out if it is intentional or not ... I was subscribed to one of them, with pretty nice history, payed 50USD/month, but 2 months from 3 he did not traded with no message to his followers ...
3. Support is very slow, nice, trying to response, but slow
4. You have no chance to discuss / rate signal providers ...
Anyway, a lot of my colleagues is using them and they are ok with ... for me, not very good.
Good luck to all