I think I'm right in saying the Stage 1 Airtec is better for a 2+ k03, whereas the Stage 2 Airtec and Peron are better for a 2+ k04 (or bigger) car.
As for charge temps over the last couple of days of 30deg+ ambient, it's really noticeable. Especially at Stage 2 with the oem cooler..! I've read conflicting reports about water meth, but it's definitely something I'm going to look into when I sort out cooling and a proper turbo.