Just came back and have been to all the lounges. Only had roughly 3.5 hours. Had enough time for LH, UA and AC but only had ~20 minutes for SQ.
Here was my route:
- Entered from T2A fast track
- Visited Lufthansa lounges (as it was just round the corner)
- Trekked to T2B
- Visited United Club
- Visited AC Maple Leaf lounge & SQ SilverKris
Food-wise, I think SQ SilverKris lounge serves much better food (probs why it's usually very crowded, compared to the opposite maple leaf lounge)!
The United Club had superb showers and toiletries (as mentioned previously) and a great bar! Didn't know there was a shirt pressing service available until I read the post somewhere above.