i haven't traded stocks, but from the little i know (and i could be wrong but).
with stocks, you have to pay a commission to trade. with forex you don't. you pay a spread which doesn't matter if you know what you are doing.
an example would be it would cost about $15.00 to $20.00 to place a limit order. I place alot of limit orders on various pairs quite often in forex since they're "free". if I did it in the stock market, i wouldn't have any money left to make a trade.
stocks close each day. forex is open round the clock.
with stocks i think there are different rules for selling vs. buying as far as account balance goes. with forex you can make money whether it goes up or down.