My S3 is 16Gb and was originally shipped with Jelly Bean. I watched a Youtube video comparing ICS and Jelly Bean and ICS was faster responding in virtually every test, despite the guy doing it being pro Jelly Bean.
I don't know much about the 'sudden death' problem with ICS on 16Gb models but from what little I've read, I thought this was more of a hardware issue due to defective memory chips and/or main boards?
My S3 updated to Jelly Bean 4.3 last December and I wasn't happy because they had removed the 3x4 Samsung keypad that I like to use. I tried a number of different keypads from Play Store but in the end decided to downgrade to 4.1.2, which went without a hitch.
My attempts to do the same with ICS 4.04 did not go so well and I'm still not sure why the IMEI was corrupted or even more surprising, that it was corrected when I re flashed 4.1.2