I must have the stealthed BIOS, as I modified my firmware some time ago, and had a selection of speeds.

Would my XBox only play stealthed images/games?

Where can I read more on this?

Can someone explain to me the difference between stealthed and non stealthed firmware?

I'm guessing it's whether or not the firmware tries to hide from detection on XBox Live.  If that's the case, why would anyone want non-stealthed?  Greater compatibility?