They should last the life of the engine, eg, as long as they are not detonated or dusted, they will last as long as regular pistons.
Remember, 207's have forged pistons, and there is no specific differences to maintenance for those vehicles.

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F.B. Racing
01 WRX (STI badged)
2010 XR5 Focus
06 Impreza Hatch 2.0i