It is still a roots blower, so it will always have a less efficient compressor and more drivetrain losses. The intercooled version has an air-water core between the SC and the lower manifold. It is a little taller and the flow out of the discharge side of the compressor is more constrained. Being air to water, the water temp is extremely critical for the cooling advantage. If it is running off chilled water, there could be some large gains from it. If it is running off engine coolent or ambiant water, it won't cool the charge much. This is basically the same setup Saleen is using with their SC kits. It is good if all you want is low end torque. It you want the fastest car, I would start looking at Vortech or Greddy first.

04' G35 Coupe(finally in the garage)
6-sp Diamond Graphite/Willow w/Premium