Bit of boring info but the 2.0 mark 4 GTI came into the country badged as a 2.0, we then slapped a silver badge on at the dealership. Generally speaking, the more red on the badge, the more horsepower but as engines have evolved over time it has become increasingly difficult to tell whats what. General rule (certainly the rule I use, is ignore the badge altogether).
Incidentally, on the Golf GT TDI 150ps, they were all badged as GTIs. Only the 150ps bora and 100/130ps Polo TDIs had all red TDI badges, oh and some Sharans but they dont really count. The quick way of telling a 150TDI and a 150Petrol Golf apart is the lower section on the front bumper. The oil burners have two extra air intakes in the outer lower corners.

VWma
indealer with a red I)