I'm amased they included 2 full games, quake 2 is open source (the engine) but the game files are commercial, don't remember about Quake tho.
As for the responcetimes, what you describe their can be atributed to the fact that you get a fast controller, fast harddrive and a fast PPC native FS.
If you ever get the chance to play with amithlon (or Umimator) you'll see this largely here aswell.
Now to make some things clear, i am not an Emuhead, i'm just using amithlon as an example.
AOS4 should also have the same feeling in speed, for basicly the same reasons given here.
Amon_Re