OK bout time i got a new GPS system

Only stipulations are i want to to have traffic updates for less then £200

Been looking at probably the Garmin C510T or the Tomtom One (TMC version)

The garmins cheaper then the tomtom, so what makes the tomtom better? cus i cant figure it out!

also anyone know what the real difference is between the Garmin Streetpilots and the Nuvis?