This one isn't exactly cutting edge for the former II users, but having been on a AX8 for a while, I'm really enjoying dual amp blocks again, and the III is fantastic with its routing and processing power.
Trying to do some Black Keys tones for example work great with two amps, say a clean Fender style and then a Plexi. Dan's running a few different amps on stage at once, and the trick is that his collection of fuzz and other effects isn't running into all the amps. No, instead he may run one style of fuzz into a clean Fender and then maybe play the Plexi on its own, or run a super fuzz into the Marshall but not the Fender, etc.
I always used to have a mindset of I'd run a pedal board, then split into two amp, when I used hardware amps, so the effects where all or nothing. Couldn't really run dual pedal chains that easily, so my way of thinking in the Axe was similar. I'd run a drive and then after the pre-amp block effects were done, I'd split to 2 amp blocks.
Now I'm learning to split the signal early, and run parallel drives, slap black delay before an amp, etc to dual amp blocks, so running essentially 2 totally different rigs, and then blending those as needed.
Again, not exactly a revolution for the II users, but if your used to working with an AX8 and one amp blocks, the ability to run essentially 2 of every single thing like amp blocks, cab blocks, reverb blocks etc is pretty fresh