now this is something i am good at
a mod chip basically just enables you to turn the mod on and off, by running hacked bios/ dashboards.
wit the upgraded hdd, it would enable you to copy games to ur hdd, run modded files, use differnet programs, nothing really special, almost the same as a softmod except that you can do two insanely awsum things
1. Turn on and off your mods (for playing live)
2. If the files get fk'd, it will re format ur hdd back to factory stock
btw: what chip do you plan to get?
xenium is good
xecuter is amazing
pm me if you want some info on a specific one