I did not see the longer time frame numbers so I based my post on shorter frame. With that said, here are my thoughts:
Interactive Brokers: I think they have zero interest in maintaining retail trader accounts. Last time I spoke to them, their retail trader accounts only allowed 1:1 leverage and charged $2 commission per trade. Commissions - Forex | Interactive Brokers
Such arrangement certainly looks like a sure try at sending a message that retail trader is not welcomed. I am grad they receive what they ask.
Gain Capital: I have tried out their demo several times. Their mobile platform on MT4 is ok. Their own mobile platform was a bit too basic, only allowed minimum lot sizes of 1000 and allowed no nano lots. If trader entered 2 positions, they were “merged” into 1. I personally found such set-up not useful to me at all, so opening a live account was not an option. They have free withdrawal for initial deposit by any profit is charged a wire fee and wire is the only way to withdraw profit.
Oanda: Decent platform, allows Nano lots, allows trader to see what each position earns. By far, the best trading set-up. Now, they charge interest rate swaps by the second. I can have a position open for 15 minutes, I will get the swap charge when I close it. There is also swap charge once a day for any position held overnight. I find by the second swap fees a bit excessive.
These are the only brokers available to all in USA. TDAmeritrade and IG Forex deserve no reviews for excluding Ohio and Arizona. I thought we parted ways with Jim Crow business model a while back, but it turns out, we are back with it.