If you talk to Amscot, ask for Sean Nofal. He can explain transaction costs to you. Brokerage is low, and while stop loss is not standard, I have been told they can easily implement on individual requests, but I don't need/use them myself.
WebIress is a very quick platform and never gets overloaded when the market is busy, the java implementation is fantastic. All depth is highlighted and coloured as it changes.
Charting has improved recently with multi-intraday charts, but charting is not it's selling point. Robustness and speed are it's main benefits.
It also has a neat excel interface for streaming data.
