The main advantage to oanda is interest on your margin deposit (credited daily), low spreads (i don't care what the spread is during news time), flexible lot size, and continuous interest payments on open positions. However, their charting does leave a lot to be desired. I use Metastock end of day for most of my analysis and oandas built in charting to view shorter time frames.
FXCM has been a fair broker, though their spreads are too high. I had a trade discrepancy with them in the past, they said it was due to a bad tick. I reentered the trade at market, and my account was credited the difference from where I was stopped out at. It is also convenient being able to fund your account with a credit card. Their free charting leaves a lot to be desired.
Forex.com, I did not like their interface and their spreads are the same as FXCM, the ability to trade/check positions from your mobile is great, but in all fairness I wasn't with them long enough to comment on anything more then that.
Actually, I would really encourage all guys to research their broker before starting up very well. It's not just you will be able to trade with low spread, and very high leverage. Security of funds is top priority if you want to expand your business.
I still insist that Oanda is the best broker around with no competitors. They provide exellent service regardless that you are being profitable sometimes - which many brokers hate.
I Love Oanda for everything but the charts. I am thinking about programming all my strategies in Metatrader so I can set alerts and have them sent to my cell phone during those bedtime hours . Then only using Oanda to place orders through > I hope they update their charting platform someday but I still think they are worth using despite that minor problem to overcome.
Oanda spreads for EURUSD is 1.5 pips during normal days, and 10 pips during weekends. Spreads can increase at certain trading times, or during major news announcements.
I have seen Oanda eur/usd gone upto 15pips 20 mins before a German zew sentiment (3 months ago). It was 20 pips just after the news and stayed like that for 334 seconed before it went back to normal spread.
This is just one of many times I have seen eur/usd spread go throgh the roof even on a moderate market voliatality.