I haven't re-installed any of my custom presets, IRs, or anything else yet - I simply turned the unit on, checked what ams and cabs etc were there, did the firmware update, and now when I try to select some blocks, the list of amps shows all the amps that were previously there, but only the new amps added by 2.3 are in bold text, and only they are selectable. Same story with the effects. And the cursor skips straight past the amps and effects that were not added by 2.3. Likewise, the cursor skips straight past the Amp+Cab section, and straight past the Cab section (becuase none of those were added by the 2.3 update).