did this exact journey with Singapore in economy, and cannot speak highly enough.

even though there are more people it has more doors and we found loading un loading quick and efficient also SIN airport is about as good as it gets to kill a few hours.

on the way back we had 5 hours and paid for a shower in the lounge, i think it was about £5 and well worth it.
IFE is great and it is all on demand.

hope this helps