Hi Steve,
Main difference is compression ratio, it's a couple of points higher on the light pressure 2.4T. The 2.4T is 2435cc, the T5 is 2319cc, which gives the T5 thicker cylinder walls for better heat dissipation. I believe the turbo on the 2.4T is slightly smaller than the on the T5 and there may be differences in the cam profiles. Volvo has made some European models of light pressure cars that were detuned via software, but not in the US market. (yet!)