Personally, its all worth.
Firstly, its a Project Butter revisit.
The battery life is either same or better, I can easily get 7 hour SOT on both.
I might not be an audiophile, but the sound seemed the same to me.
Conclusion for me, I'm never turning back to 4.2.2(unless there is a major test), because 4.3 is far far better.
You should do more reading on more benefits, its in the general thread.
Name: Nexus 4 Mako
ROM: BrainMaster JWR
Kernel & Tweaks: Franco/Trinity
Devices I once had(Or still have):
LG Nexus 4(present), Samsung Nexus S(present), LG Optimus 4X HD P880(sold), HTC Sensation XE Pyramid(sold), Samsung Galaxy Wonder i8150(spare)
Devices I have minor experience about:
Samsung Galaxy Y, Samsung Galaxy i9100, Samsung Galaxy i9100G, Samsung Galaxy SIII Mini i8190N, HP iPaQ500(retired and yes its an antique)