I can answer this one as I've just got back. The difference between SYD and SIN NYE:
* SYD's fireworks are 7 minutes longer and 7 times better (although the Marina Bay Hotel is a spectacular backdrop). Winner: SYD
* SIN's hotels are 7 times cheaper (yes, I stayed at the Ascott Raffles, a 5 minute walk from the grassy area by the bay). Rate was AUD$250. Winner: SIN
* That grassy viewpoint? Personal space was huge - no seriously people 3 feet behind and 3 feet ahead, not crowded at all. Winner: SIN
* Booze: My wife had an afternoon glass of Sav Blanc at The Pelican. It cost $21 inc GST. Ouch. Winner: SYD
* HOWEVER: wine is so expensive in SIN you may as well drink French bubbles, which we did! Bottle of Oz Sav Blanc from the bottleshop? $33 (would be $16 in AU). Bottle of MOET? $60 (same price as AU). Winner: ahhh, call it a draw
* Hassle of getting to/from: in SYD, you want a good view, you queue from minimum 3 pm. In SIN? Hah! We left our hotel at 11:40 pm to wander over!!! In bed at 12:40. Winner: SIN
* On New Years Day most shops were open. The Lau Pa Sat hawkers market do some lovely cheap easts, Maxwell Centre had the best BBQ chicken I've ever tasted. Also, where was the street rubbish lying around the place? Oh, in the bins maybe? Winner: SIN.
* Finally: Changi. Full-size X-Wing replica. SilverKris Lounge (Taitinger with your goat's cheese pie sir? Yes please). And climbing onboard a factory-fresh 777-300ER new J fitout (the pilot advised delivered 5 days ago). Lobby Thermidor ok a touch overcooked but damn nice anyway. Winner: ...do I even need to say?