The only platform I would say beats StreetSmartPro (and Cybertrader) hands down would be Tradestation, which gives you all the same stuff (r-t charting, news, etc.) but also backtesting and scanning ability. Trade for 1.5 cents/share but pay for the platform and services you choose -- can get a good package for under $200/mo..
IB's platform is the fastest for nimble day-traders IMO, with only two clicks to place a trade.