I read really good reviews of one in cyprus. Is there any disadvantage to doing this, as opposed to using a broker in my country (the us)?
It depends on if you consider the broker stealing your money to be a disadvantage? 
Cyprus, Isle of Man, and a few other places don’t regular forex brokers. Anyone with $20 can start a website and be a legal forex broker. You want to stick to major brokers in countries such as the US, UK, and Australia.
If you pick one of the “big boys” like Oanda, IBFX, Alpari, GFT, etc then you will not get ripped off.
qazwsxedc, you know. the real deal with overseas brokers is not that gloomy as might seem at first sight. There was an example of broker located in Cyprus. I can say that the location has almost nothing to do with a broker aiming at ripping clients off. The reason why people are very discreet about the location is that they do not actually realise how it works. Many territories are off-shore territories where the taxing is not that strikt. That’s all. Hence, such brokers offer far more possibilities for traders. If you’re interested, I can advise you of one bood broker, which has been successfully doing its business for over three years