Matrix/Xodus chip questions...
 

Who has this chip, and what do you think of it? Does it play all backed-up games/imports? Once it is installed, can I take it out and install the systems original bios if neccessary (so it'd be like it was never there) to enable Xbox Live play? Any comments on it would be helpfull.

Also, can I return it to the site I bought it from if I choose not to install it?

Modchips ussually play all backups and imports, and yes, they can be taken out. Also, some modchips have on/off switches, so you don't need to remove them

As for return policies, totally up to the store. But is unlikely.