Surely that's a given?!

 

That was given, Galaxy S3's ICS ROM has many features Cyanogen (and therefore stock Google Android) doesn't have. Just wait for the official JB by Samsung.

 

I installed the wanamlite JB ROM which is supposedly a modded leak ROM (?) and it's buggy. I do believe the bugginess is down to me not doing a wipe install, but it shouldn't need it.
Apps crash all the time (especially contacts, which is annoying) and I'm sure the macro setting from my camera has vanished. Some added features are nice, but nothing special.
Also, I must've totally misunderstood what Google Now/Voice was. Was expecting it to be a replacement for S Voice, but apparently it's just the age old chrome voice search on steroids. You can't launch apps from it, nor can you use it to call/txt anyone (think I managed 1 call out of 10000000).

 

Its buggy because its based on a leak and not the final release.

 

AOSP is not better on this phone. Most of teh features, Samsung developed and as such are only available oN samsung roms.