A chargecooler is more efficient at removing the heat as it's a water-based system, working in a similar (well, identical) way to the radiator that keeps your engine cool. Water is a more efficient conductor of heat than air, and a CC setup is particularly better suited to hot climates as you won't suffer from heat soak anywhere near as much as an IC setup. Granted that's less of an issue with an SC car than a TT one, but it's still a better solution in most cases. The only downside is cost and space needed.
Be interested to hear about your brother's setup on the Esprit, got any more details on what he did?