WIth Ib you get an added advantage
Since it's Equity division is SIPC protected the excess funds from the Futures or FX trading are swept in to that account Thus giving you some protection
And you can trade all 3 from 1 A/c + low comms!
Negatives:
Platform bit tedious
Min A/c 10K
Concerning the low commissions if you move around enough liquidity, then the commissions can be around $0.0005/share, which is entirely offset by the add liquidity rebates from most exchanges.
Negatives:
Requires $25,000 per trade for Forex. Orders less than that amount are routed to odd lots.
USD US Dollar 25,000 7,000,000
AUD Australian Dollar 25,000 6,000,000
CAD Canadian Dollar 25,000 6,000,000
CHF Swiss Franc 25,000 6,000,000
CNH China Renminbi (offshore) 160,000 40,000,000
CZK Czech Koruna USD 25,000(1) USD 7,000,000(1)
DKK Danish Krone 150,000 35,000,000
EUR Euro 20,000 5,000,000
GBP British Pound Sterling 17,000 4,000,000
HKD Hong Kong Dollar 200,000 50,000,000
HUF Hungarian Forint USD 25,000(1) USD 7,000,000(1)
ILS Israeli Shekel USD 25,000(1) USD 7,000,000(1)
KRW Korean Won 50,000,000 750,000,000
JPY Japanese Yen 2,500,000 550,000,000
MXN Mexican Peso 300,000 70,000,000
NOK Norwegian Krone 150,000 35,000,000
NZD New Zealand Dollar 35,000 8,000,000
RUB Russian Ruble 750,000 30,000,000
SEK Swedish Krona 175,000 40,000,000
SGD Singapore Dollar 35,000 8,000,000