Mostly we'll just have to agree to disagree but one thing you say is incorrect.

While it has the best DD out there, both the PS2 and GC can do it, though not quite as easially for the programmers by what I understand.

The GC doesn't have a digital audio output so it is not physically capable of outputing Dolby Digital.

The PS2 has no hardware capabilities for DD encoding. EA has implemented DTS encoding in software for a few games. The other 99% are 2 channel.

I think DD makes a big difference in the overall experience. Other differences aside, PGR is a more immersive and viscerally involving game than GT3 because of the well implemented discrete surround. I do play on a 100" screen with a 7.1 surround system. Immersion is important to me.

-Dylan