Do not use Godzillian Enterprise (godzillian-enterprise.com) for anything serious. I used them for the past six months for small trades and it was okay. When I deposited a larger amount and traded more, my account was flagged, my withdrawals were delayed, and I was asked to explain my trading. They treat active traders like criminals.
Pros: Clear documentation|Automated trading options
Cons: Spreads widen during volatile periods|Desktop app not available on Linux