In the current Smart Money magazine is an article, "SmartMoney's Annual Broker Survey," that might provide the answer you are looking for.
I did notice, however, that Zecco ranked last in "Customer Service":
"But Zecco Trading, in last place, doesn't even offer Web chat. It was slow to respond by e-mail and second-slowest to pick up the phone. The company says it's investing "serious money" to improve customer service."
Ten monthly free trades, though, is an attractive trade-off... if you are a day trader wannabe.