Spreads are fantastic, but not open 24 hours (for the insomniac forex traders), and selection is relatively limited (although fine if you mostly want to trade indices, UK shares, commodities and common currency pairs).
Update: If your stop is hit then don't expect it to be filled for a long time. Regardless of whether the price crosses your stop price repeatedly. If my top is hit then I like to see the position close if I'm trading a highly liquid market such as FX. This could be a cause for concern because it suggests that games are being played with open positions.
Pretty good. Fast execution, no requotes & tight spreads. But trading stops at 21:00, spreads increase at 16:00 and the web-interface is very poor. If you like to place limits and stops then expect to have to place 3 separate orders, completely unacceptable in this technological age (IGindex sets the standard in this area). Another significant downside is that it takes eons for the screen to update (>5 min) if you're limit or stop has been hit and this can severely impede decision-making. On the plus side, one doesn't feel like one is being ripped off by the firm unlike some other SB companies.