Did you arrive on 8/8 at SFO? (actually AM of 8/9 due to the gate delay at SFO...) If so, I was on the same flight. The J class was actually not full on the flight as a family of 3 we know was upgraded from PE. But somehow SQ did not allow me to upgrade my son's PE with miles at all for this leg and I was able to do it from the SQ1 leg.
I agreed with you that the food quality did seem to be off but the service was superb compare to CX. The HKG Kris Lounge was too packed though. My wife will be flying F in November, let's see how that go.