Killed = Bionic
Phone graveyard = D1
Resting = Dx
I also stayed firm, but polite, the entire time. Took a few calls, and I had a legitimate reason (the audio hiss)
This has a been a chronic problem for me as well. After a lot of experimentation I've got my phone in a tolerable condition. I tried a bunch of different combinations of settings and in the end I settled on both "animation scale" settings at .5x. Also, I switched back and forth between GO and Nova (Prime) launchers, and found that Nova is not as laggy.
What I found particularly useful, although I cannot confirm the correlation/causation factor, was to do a cache wipe in recovery and phone reboot each time I made a change. When it starts to get a little laggy I'll do another cache wipe.
Whatever happens, I do not want to re-install and I don't want to do another factory data reset. I did an FDR right after updating via the HoB and I'd rather not go through that again.
Samsung Galaxy S4 Developer Edition