Travelling by Singapore Airlines has always been a pleasure - first time and every time - especially so on their long haul fights. The cabin attendants and the ground staff are very courteous and do respond to your requests very well. The flight plans are very punctual and you can be rest assured that your flight leaves on time. The food served on board (best chosen at the time you book your tickets) are of high quality, though there is room for improvement when we talk about strict Asian vegetarian meal.
During your long haul journey, courteous in-flight attendants take care of your every need and also the quality of entertainment on board is rated one of the finest in the world.
The seating (I travelled by Economy Class on a Boeing 747 Megatop) is very comfortable. But if you happen to get a seat next to the restrooms (toilets), you may be in for an uncomfortable journey. The seats reclines a bit more than half when compared to reclining angles on other seats and especially on a long haul flight this may prove very daunting. Oh! not to worry, whatever it takes, you will not be bothered about smelling toilets.
Travel Tip: In flight, especially on long haul flights, drink lots of fluids as advised by Singapore Airlines in-flight video - keeps your body cool and skin moist.
If you have any questions about the dimensions of check-in baggage, the airline tele-representatives appear a bit confused. They cannot clearly relate about check-in baggage dimensions.