What have you got on at the moment.
The original GTI/Ed30 one is not great to be honest. I changed mine to the later revised (non alloy ends) Golf 6R/TSI/S3 8P intercooler and noticed a vast improvement on a Stage 1 GTI. It is deeper, has a more efficient core, and fits perfectly while also deleting the old bayonet hose connectors that leak boost.