I know GCC 3.0 on x86 has many more advantages such as optomisations. I think there was some GCC 3x benchmarks compared to the 2.95 for compiled applications. GCC 3 came out on top...
But im not sure how this does it for PPC. Also, i think one of the GCC compilers has PPC support. This is why Hyperion or someone else may go with GCC 3 instead of 2.95, because 3 has the PPC stuff and not 2.95.. thats pure speculative though, i dont know for sure... I did hear something like that... Maybe it was GCC 3 had vector support....