Flying on SQ is always a pleasure whether you are in First, Business or Economy class. This airline, although usually the most expensive option for any given route, is worth the extra cost because they pay attention to the details.
The entertainment system in economy class is better than some carrier's business class.
Equipment and staff are usually "top-notch".
Of course there are glitches here and there but this airline strives to be the best at everything that they do...they get it right 90+ % of the time.