overall I would say they are very good, I like them as a broker, you can always use a different charting package if you like, just look at what they offer as an order execution platform from a chart.
other than that they pay interest by the second, not excactly the same rates as the central banks though.
the one think i dont like about them is as currency rates start moving your relative value in the position either increases and decreases to reflect the updated currency rates.