I stayed a full week at the John Hunter, mostly because, like August, I had a baby in NICU and I had a private room. They told me I could stay longer as a "boarder" if I wanted, but we live in town so I didn't need to. It was my 2nd c/sec and I felt good enough to go home after 3 days. I'm sure I could have discharged at that point, or gone home AMA if I had wanted to. I didn't because:
1) The easy NICU access was important
2) everyone else in the family was sick
3) I had an 20 month old who wanted to be picked up
After my first caesarean, first baby, I was discharged at 3 days--delivered Thursday pm, home on Sunday morning. This was not long enough. After my second c/sec, I could tell the next day that I felt much better than after the first one--ironic that I needed to stay for other reasons!
It should be based on your own comfort level--physical and psychological--and you don't always know in advance how you will feel. I think it's important to be flexible, both ways.